Homalium sect. Rhodonisa (Tul.) Sleumer in Bull. Jard. Bot. Natl. Belg. 43: 300. 1973.

Nisa [unranked] Rhodonisa Tul., as “Rhodonisae” in Ann. Sci. Nat., Bot. sér. 4, 8: 70. 1857.

Typus (designated by Sleumer, 1973: 300): Nisa sanguinea Boivin ex Tul. (≡ Homalium sanguineum (Boivin ex Tul.) Baill.).

Stipules axillary, free, usually rapidly caducous. Inflorescences axillary, spiciform to racemose or paniculate; bracts broad (sometimes rather short), bracts and bracteoles persistent. Flowers short-pedicellate, with pedicels articulated usually just below the receptacle, to subsessile or sessile; perianth 4–5(–6)-merous; sepals oblong, sometimes broadly or narrowly, to somewhat obovate, ovate, or elliptical (seldom to oblanceolate or lanceolate), slightly accrescent and usually curving over the fruit; calyx tube tubular with a narrowed base, often visibly ribbed or grooved, to funnelform, in fruit tubular to turbinate or ellipsoid; petals obovate to oblanceolate with rounded (to obtuse) apex, much longer than sepals, ascending (spreading), at least slightly accrescent (where known); sepals and petals ciliate, usually shortly, or not; sepal glands of moderate size, broadly elliptical to rounded (somewhat oblong or trapezoid), glabrous; stamens 1 per petal, inserted between glands; anthers varying from broadly oblong-elliptical with oblong-elliptical locules, the slits of dehiscence nearly parallel, to small, transversely elliptical with subglobose locules, widely separated lateral slits towards apex (sometimes apparently or nearly basifixed with connective not prominent); upper surface of ovary sometimes quite narrow, nearly flat to shallowly conical in flower, in fruit convex to conical (or little expanded); styles (3–)4–5, usually fused (or connivent) for at least half of length (sometimes only shortly). Locule of fruit narrowly cylindrical or ellipsoid (to narrowly obovoid), pubescent throughout; seeds 2–4 per fruit, small (possibly no mature seeds seen).

Notes. – Adequate molecular data to elucidate relationships among the very diverse, probably paraphyletic lineages of Homalium do not exist. The relationships of species of sect. Rhodonisa would be of particular interest. The genus as now circumscribed has an apparent division between Homalium sect. Homalium and similar sections (e.g., in Madagascar, Eumyriantheia and Nisa) and sect. Blackwellia Benth. and related sections (primarily Polyanthera). Species that are typical of the former group have relatively few (4–7) broad sepals and petals; relatively large, broadly elliptical anthers; large sepal glands; and broadly funnelform calyx cups in flower. Sepals and petals are usually different in shape and may differ in size or accrescence. Typical species of sects. Blackwellia and Polyanthera have often more numerous, narrow sepals and petals, which usually are similar in shape; often small broad anthers with subglobose locules (though broadly elliptical anthers are also seen); and often narrowly funnelform to tubular, ridged calyx cups. The upper surface of the ovary is often prominently conical. Sect. Rhodonisa includes species that have relatively few, broad petals and sepals, like sects. Eumyriantheia and Nisa, but often elongated, narrow, ridged calyx cups, and sometimes also small “Blackwellia-like” anthers with subglobose locules. These species are not easily classed as belonging to either group of sections, which is one reason for this author's preference not to recognize subgenera (Applequist, 2016a).

Sleumer (1973) recognized two red-flowered species, H. sanguineum (Boivin ex Tul.) Baill. and H. rubriflorum Sleumer, and one white-flowered species, H. albiflorum, within sect. Rhodonisa. Red flowers are rather unusual in Homalium, though not unknown from other sections, and the two red-flowered species are also distinguished from the H. albiflorum complex in having long-branched paniculate inflorescences and flowers borne only 1 or 1–2 per node and bract (rather than in clusters of 2 or more). The taxonomy of the red-flowered species is not problematic, and no undescribed similar species were identified.

However, the populations with clustered whitish (occasionally to yellowish or greenish) flowers, which Sleumer (1973) subsumed within H. albiflorum, appear actually to represent no fewer than ten distinct taxa. These seem to fall roughly into two clusters. Homalium albiflorum s.str. (Fig. 1) and three new species, H. analavelonae Appleq., H. ihosyense Appleq., and H. phillipsonii Appleq., have usually five petals (varying to four or six); the outer surfaces of the sepals are sparsely pubescent or pilose, and the petals are at least sparsely pubescent (to pilose or glabrescent) with ciliate margins. Two previously described segregate species, H. leucophloeum (Tul.) Baill. and H. baillonii Scott-Elliot, and four new species, H. megaphyllum Appleq., H. pseudoracemosum Appleq., H. rakotovaoi Appleq., and H. vohitsiandrianense Appleq., have usually four petals (seldom to five in two species), glabrous or glabrate sepals, and glabrous petals without ciliate margins (except that in H. pseudoracemosum sepals are sometimes sparsely pubescent and petal margins are sometimes ciliate). These groups differ in ecological preferences, with the H. albiflorum group preferring arid to subhumid western and northern habitats and the H. leucophloeum group mostly in central and eastern (or extreme northern) forests that are humid or at least less arid (Fig. 2). An outlier is H. pseudoracemosum, a western species which is morphologically more similar to H. albiflorum than others in this group, and which may represent a transitional form between the two groups.

1. Homalium albiflorum (Boivin ex Tul.) O. Hoffm., Sert. Pl. Madagasc.: 18. 1881.

= Nisa albiflora Boivin ex Tul. in Ann. Sci. Nat., Bot. sér. 4, 8: 71–72. 1857.

Holotypus: Madagascar. Reg. DIANA [Prov. Antsiranana]: Nossi-bé, s.d., fl., Pervillé 480 (P [P04679107]!; iso-: L [L0010874 fragment] image seen).

= Homalium hoffmannianum Baill. in Bull. Mens. Soc. Linn. Paris 1: 575. 1886. Holotypus: Madagascar. Reg. DIANA [Prov. Antsiranana]: “ins. Sakatía prope Nosi-bé”, II.1880, fl., Hildebrandt 3357 (P [P04679110]!; iso-: B [B10 0153999 fragment] image seen, BM, G [G00018422, G00018423] images seen, GOET, K [K000231487] image seen, L [L0010873] image seen, M [M0109536, M0109537] images seen, WU).

Tree to 15(–20?) m tall, 15 cm dbh, or spreading shrub; bark gray or mottled green, gray and white, caducous in plaques or smooth; twigs pale to grayish (dark) brown, glabrous (sparsely to moderately short-pubescent). Leaves elliptical to broadly elliptical (ovate, very rarely narrowly elliptical to lanceolate), (4.5–)5–16.5 × (1.9–)2.8–8 cm, relatively thin-textured and often appearing slightly wrinkled; margin crenate to crenulate (subentire, crenate-serrulate); base convex to rounded (rarely rounded-truncate, shallowly cordate); apex acuminate to cuspidate, seldom acute (partly obtuse, rounded, or emarginate); both surfaces glabrous (rarely sparsely short-pubescent especially on midrib abaxially, then sometimes also along veins adaxially), drying brown or less often green, the adaxial surface darker to blackened; secondary veins moderately prominent, tiny domatia rarely present; petiole sometimes red, (1–)5–18(–25) mm, glabrous (rarely sparsely to moderately short-pubescent). Inflorescences racemose (partly short-branched paniculate), (3.5–)6–10(–15) cm; peduncle (0.6–)2–5(–6) cm; rachis above peduncle moderately to densely pubescent at least in patches; flowers usually (2)3(4) per node; pedicels (0.5–)1–2(–3) mm, densely pubescent (pilose). Flowers 5(6)-merous, white to cream; sepals narrowly oblong (ovate), (0.6–)1–1.8(–2.5) mm, sparsely pubescent (sparsely pilose) outside, margins minutely ciliate; sepal glands orbicular to irregularly trapezoid (broadly elliptical), (0.3–)0.5–0.6(–0.8) × (0.3–)0.5–0.6 mm; calyx cup densely to moderately pubescent (sparsely pubescent, sparsely pilose); petals obovate, 2.6–8 mm, accrescent, sparsely to moderately short-pubescent on both surfaces (to moderately at base, rarely glabrescent), margins minutely ciliate; filaments 0.8–2.5 mm; anthers transversely elliptical, 0.2 mm high (seldom broadly elliptical, to 0.3 mm, especially in northern populations).

Vernacular names. – “Gaviala” (Randrianarivelo et al. 188); “Hazoadala” (Service Forestier 8330); “Hazoambo” (Randrianaivo et al. 1159, Service Forestier 7019).

Distribution, ecology and conservation status. – As herein circumscribed, H. albiflorum is restricted to populations from northern and western Madagascar (Fig. 2). It is still a fairly widespread species, occurring in dry forests, or occasionally in low-altitude humid or transitional forests in the north, on sand and limestone. It has been reported to occur along stream margins and to be locally frequent. It occurs in protected areas including Analamerana, Oronjia, Montagne des Français, Bemaraha, and possibly Ankarafantsika. Its conservation status is estimated as “Least Concern” [LC].

Notes. – As previously circumscribed (Sleumer, 1973), H. albiflorum encompassed a great range of morphological character states and was distributed almost throughout the entire country of Madagascar (Fig. 2). It is herein restricted to populations with usually elliptical to broadly elliptical leaves, well-developed peduncles, partly pubescent rachises, at least sparsely pubescent perianths, and 5(6)-merous flowers (Fig. 1).

Homalium albiflorum continues to encompass a broad range of morphological variation, possibly due in part to hybridization with or introgression from related species. In northern populations it sometimes has narrow leaves, broadly elliptical anthers, sparse pubescence on the abaxial leaf surface, and/ or occasional domatia. The specimens Afzelius s.n. and Noyes et al. 1061 are identified below as suspected hybrids involving H. pseudoracemosum, but it is possible that they represent aberrant individuals of H. albiflorum. A few other northern collections identified as H. albiflorum have unusually narrow leaves. Below, northern collections with pilose indument that appear morphologically consistent with H. phillipsonii or intermediates between that species and H. albiflorum are noted under that species.

The publication of Nisa albiflora (Tulasne, 1857: 72) cited the collection numbers Pervillé 480 and Boivin 2124 (said to come from “in Macroneso adjacenti”). The only known complete specimen has a handwritten label stating that it was collected by Pervillé under the number 480; below that on the same label is the notation “2124. Nossi-bé. Bernier comm. 1846”. A preprinted label referring to Boivin's 1847–1852 voyage was applied in Paris with the handwritten annotation “2124”. This appears to be the origin of an incorrect citation by Tulasne of Boivin. Thus, the name was based only on the single sheet of Pervillé 480 at P (the fragmentary material obtained by L clearly not having the status of a second duplicate). The P specimen was designated as lectotype by Perrier de la bâthie (1940: 925) but the designation was unnecessary as it is properly regarded as a holotype.

Afzelius s.n. and Noyes et al. 1061 have abnormally narrow leaves and are from the western portion of the range, sympatric with the probably closely related H. pseudoracemosum. They are suspected of having hybrid ancestry.

Additional material examined. – Madagascar. Reg. Boeny [Prov. Mahajanga]: env. de Majunga, 2–15 m, 28–30.XII.1924, fl., Humbert 4054 (G, P); Majunga, I.1919, fl., Perrier de la Bâthie 12350 (P); RN 7 [Ankarafantsika], canton Tsaramandroso, distr. Ambato-Boeni, 20.II.1953, fr., Réserves Naturelles 5137 (P); “Ankarafantsika?”, s.d., fl. & fr., Service Forestier 88 (P); Analabe, Soalala, 26.I.1956, fl., Service Forestier 15912 (P). Reg. DIANA [Prov. Antsiranana]: Réserve Spéciale d'Analamerana, near Antafiamantsina at the mouth of the Irodo River, valley of the Ampondrakely river, 12°41′46″S 49°34′30″E, 100 m, 20.III.1994, fl., Du Puy et al. M743 (MO, P); env. de Diego-Suarez, forêt d'Orangea, 1–100 m, 22.I.1960, fl., Humbert & Cours 32287 (P); ibid. loco, s.d., fl., Humbert & Cours 32288 (P); Orangea, 12°15′01″S 49°21′39″E, 50 m, 20.I.2003, fr., Miller et al. 10725 (MO, G); 2 km W d'Ambolobozobe, forêt d'Ankonahona, 12°31′26″S 49°31′29″E, 20 m, 25.I.2007, fl. & fr., Rakotonandrasana et al. 1084 (G, MO); 1 km NW d'Ambolobozobe, 12°31′S 49°31′E, 26.XII.2007, fl., Rakotonandrasana 1231 (MO); Montagne des Français, forêt d'Ampitiliantsambo, 12°23′13″S 49°23′04″E, 205 m, 14.I.2005, fl., Randrianaivo et al. 1159 (MO, P); Fkt. Andranomanitra, campement Antafiankovoka, Montagne des Français, 12°21′15″S 49°21′40″E, 166 m, 3.II.2005, fl., Randrianarivelo et al. 188 (G, MO); Mont Andrahona, 3 km NE d'Andrafiabe, 12°28′49″S 49°26′56″E, 400 m, 31.I.2005, fl., Ratovoson et al. 826 (G, MO, P); 1 km NE d'Ambolobozobe, forêt d'Ampanasagna, 12°31′01″S 49°32′14″E, 50 m, 1.II.2005, fl., Ratovoson et al. 834 (MO, P); Sadjoavato, forêt de Sahafary, 12°36′26″S 49°26′43″E, 280 m, 8.I.2007, fl., Ratovoson et al. 1214 (MO, P); Orangea, fkt. Ramena, 12°14′39″S 49°22′47″E, 12.II.2005, fr., Schatz et al. 4235 (MO); forêt de Sahafary, 27.II.1953, fl., Service Forestier 7019 (MO, P); Massif d'Ampitiliantsambo, 19.II.1954, fl., Service Forestier 8330 (P). Reg. Melaky [Prov. Mahajanga]: Beanka, partie S, Sarodrano, 18°03′29″S 44°30′53″E, 337 m, 4.III.2012, fr., Hanitrarivo et al. 246 (MO); Tsingy du Bemaraha, 1932–1933, fl., Leandri 357 (P); calcaires de l'Antsingy, vers Ambodiriana (E d'Antsalova), 100–150 m, 21–27.I.1960, fl., Leandri & Saboureau 2693 (MO, P); Distr. Antsalova, 22.I.1959, fl., Réserves Naturelles 10234 (P); Bemaraha, aux env. de Tsiandro, 26.XI–3.XII.1952, fl., Service Forestier 6776 (P [2 sheets]); forêt Ambereny, distr. Antsalova, 11.VIII.1954, fl., Service Forestier 10555 (P). Reg. Menabe [Prov. Toliara]: Kirindy, 22°10′S 44°05′E, 17–18.IX.1994, fl., Randriamarosoa et al. 194 (P). Reg. SAVA [Prov. Antsiranana]: Daraina, forêt de Solaniampilana-Maroadabo, 13°05′19″S 49°35′05″E, 140 m, 11.III.2004, fl., Gautier et al. 4565 (P); Vohémar, Amboay 6 km SW de Fanambana, forêt de Analalava, 13°35′35″S 49°58′38″E, 260 m, 24.XI.2000, fl., Randrianaivo et al. 607 (G, P); Analafiana, Vohémar, 14.XII.1955, fl., Service Forestier 15670 (P). Reg. unknown: sine loco, s.d., fl., Petit-Thouars s.n. (P [3 sheets]).

Possible hybrid specimens. – Madagascar. Reg. Boeny [Prov. Mahajanga]: Majunga, 16.VI.1912, fl., Afzelius s.n. (MO [2 sheets], P). Reg. Menabe [Prov. Toliara]: 55 km NE Morondava, CFPF forestry concession, Kirindy Forest, 20°04′S 44°40′E, 35 m, 23–24.III.1992, fl., Noyes et al. 1061 (MO, P).

2. Homalium analavelonae Appleq., sp. nov. (Fig. 3).

Holotypus: Madagascar. Reg. Atsimo-Andrefana [Prov. Toliara]: forêt d'Analavelona au N du Fiherenana, 950–1250 m, III.1934, fl., Humbert 14236 (P [P04679164]!; iso-: G [G00341928] image seen, P [P04679167, P04679171, P04679172]!).

Homalium analavelonae Appleq. differs from H. albiflorum (Boivin ex Tul.) O. Hoffm. in its short peduncles, villous rachises, and usually larger anthers.

Tree to 12 m tall; twigs dark gray, glabrous. Leaves broadly elliptical to elliptical or broadly obovate, 5.4–12.2 × 3–7.5 cm, relatively thin-textured; margin shallowly or inconspicuously crenulate; base rounded (convex); apex cuspidate to emarginate (rounded-obtuse); both surfaces glabrous, drying greenish to pale brown, sometimes discolored adaxially; secondary veins somewhat prominent; petiole 11–21 mm, glabrous. Inflorescences racemose, immature 2–4 cm with possibly zigzag rachis; peduncle 0.2–0.6 cm; rachis villous; flowers 2–3 per node; pedicels 1–2 mm, pilose. Flowers probably 4–5-merous, white; sepals in early flower oblong-ovate to oblong-lanceolate, 1.5–1.7 mm, sparsely pubescent with few long appressed hairs outside, inside sometimes glabrate, margins long-ciliate; sepal glands c. 0.4 × 0.3 mm; calyx cup pilose; petals obovate, in early flower 3–3.7 mm, accrescence unknown, sparsely appressed-pubescent with sometimes long trichomes on both surfaces, margins short-ciliate; filaments 0.6–0.8 mm; anthers broadly elliptical, 0.3 mm high.

Distribution, ecology and conservation status. – Homalium analavelonae is known only from one collection from the southwestern massif of Analavelona (Fig. 2). Analavelona is a sacred forest and has some level of protection. Because this forest is subhumid, while forests in surrounding areas are dry (and highly degraded or lost), the species is unlikely to occur anywhere else. This means that the species is vulnerable to having its entire population affected by a single event, so a preliminary assessment of its conservation status is “Vulnerable” [VU D2].

Notes. – Homalium analavelonae is presumed to be closely related to H. albiflorum s.str. That species has elliptical to broadly elliptical (or rarely ovate or narrow) leaves, longer racemes with well-developed peduncles and pubescent indument, and usually smaller transversely elliptical anthers (especially in its southern distribution). Its pedicels and calyx are usually pubescent (though rarely pilose) and the indument on the petals sometimes moderately dense but short. Many leaves of the type collection of H. analavelonae are damaged or irregularly shaped.

3. Homalium baillonii Scott-Elliot in J. Linn. Soc., Bot. 29: 23. 1891.

Holotypus: Madagascar. Reg. Anosy [Prov. Toliara]: Fort Dauphin, VI.s.a., fl., Scott Elliot 2853 (K [K000231483] image seen; iso-: BM, P [P04679196]!).

Tree to 12(–20) m or shrub; twigs pale, grayish (dark brown), glabrous. Leaves broadly elliptical to elliptical, (5.3–)6.2–12(–15) × (2.8–)3.5–8.5 cm, fairly thick-textured; margin subentire to very shallowly repand; base broadly convex (rounded, often minutely attenuate at extreme base); apex cuspidate (partly obtuse, rounded, or emarginate); both surfaces glabrous, drying greenish or brownish, the adaxial surface usually darker (to blackened); secondary veins little prominent; petiole sometimes red, (10–)14–28(–33) mm, glabrous. Inflorescences racemose, (2.5–)5–15 cm; peduncle 0.1–0.6(–1.2) cm; rachis glabrous; flowers (1)2–3(4) per node; pedicels 0.5–1 mm, sparsely pubescent to glabrate, or flowers sessile. Flowers 4-merous, whitish (pinkish white); sepals oblong to broadly oblong (slightly obovate), 1.8–2.6 mm, glabrous except margins sparsely short-ciliate; sepal glands broadly oblong or elliptical to orbicular, 0.5–0.7 × 0.4–0.5 mm; calyx cup glabrous (sparsely short-pubescent); petals narrowly obovate, 4–8.5(–10.3) mm, accrescent, glabrous, margins not ciliate; filaments 0.9–1.3 mm; anthers broadly elliptical (or transversely elliptical?), 0.3 mm high.

Vernacular names and uses. – “Hazoala” (Randrianaivo et al. 2364); “Lalampito” (Service Forestier 7775); “Lampivahatry” (Randrianaivo et al. 2364); “Lapivahatra” (Ramison & Armand 313); “Lohariana” (Réserves Naturelles 3813); “Menaky” (Ludovic 1584); “Takonandro” (Service Forestier 1553, 5324); “Tapinandro” (Ludovic 1697,1763); “Tsihanimposa” (Ratovoson 1901); “Tsitakonandro” (Service Forestier 7775); “Tsivalandra” (Réserves Naturelles 7471); “Tsivalandravy” (Réserves Naturelles 7470); “Voankazonala” (Randriantafika 61).

Wood is used for domestic heating (Ludovic 1584, 1763) and trunks are used for construction of traditional houses (andavany; Ludovic 1697, 1744, 1763) and planks used to make household furnishings (Ludovic 1763).

Distribution, ecology and conservation status. – Homalium baillonii is endemic to southeastern Madagascar (Fig. 2). It occurs in littoral forest or low-altitude humid forest, on sand. Its habitat includes the protected areas of Mandena, Ste. Luce, and Andohahela. The EOO is estimated as 10,895 km2, and the AOO as 64 km2. However, the large majority of accurately located collections occur in a very small area, and it is not evident that more than ten distinct populations exist. Because the unprotected portions of the habitat are suffering ongoing anthropogenic degradation and loss, a preliminary estimate of the species' conservation status is “Vulnerable” [B1ab(iii)+B2ab(iii)]. The species was collected outside the Anosy region once in 1954 and never again since then, despite repeated botanical collections in remaining low-altitude and coastal forests. If that population were excluded as probably extinct, the EOO would be estimated as 1403 km2 and the AOO as 60 km2.

Notes. – Homalium baillonii, which was lumped by Sleumer (1973) into H. albiflorum, is herein reinstated as a distinct species. It is distinguished by many characters, including its thick-textured leaves often with subentire margins and proportionally long petioles; short-peduncled, glabrous inflorescences; flowers tetramerous and very short-pedicellate or sessile; and glabrous sepals and petals (except for ciliate sepal margins). Additionally, it is native to southeastern Madagascar and has clearly different ecological preferences (Fig. 2). It is much more similar to H. leucophloeum, also herein removed from H. albiflorum, which almost always has sessile flowers and has proportionately narrower and on average somewhat shorter leaves, which usually have shorter petioles than those of H. baillonii and slightly more prominent veins. That species occurs farther north than H. baillonii, and at least usually at higher elevations.

Additional material examined. – Madagascar. Reg. Anosy [Prov. Toliara]: Fort Dauphin, VII.1890, fl., Catat 4317 (P); Fort-Dauphin, 28.VI.1926, fl., Decary 4182 (P); Fort-Dauphin, 1.VII.1926, fl., Decary 4245 (P); Pointe Itaperina, distr. de Fort-Dauphin, 13.VII.1932, fl., Decary 10126 (P); Mandena, 24°57′S 47°00′E, 0–10 m, 17.IV.1989, fr., Dumetz et al. 684 (P); Mandena, 24°57′S 47°00′E, 0–10 m, 25.X.1989, fr., Dumetz et al. 790 (MO, P); Andohahela RNI, près du village Taviala-Andohavondro, 24°59′S 46°43′E, 175–200 m, 28.VI.1995, fl., Eboroke & Paul 1042 (G, MO, P); N side of Antorendrika River 22 km NE Tôlanaro, 0–20 m, 22.III.1989, fr., Gereau et al. 3308 (MO, P); Entre le pic St Louis et la mer, 1–5 m, 20.IX–6.X.1928, fr., Humbert 5985 (P); forêt de Fasimalandy, 24°42′41″S 47°11′18″E, 15 m, 31.VIII.2012, fl., Ludovic 1567 (MO); forêt d'Ampasipotsy, 24°43′03″S 47°11′09″E, 17 m, 3.IX.2012, ster., Ludovic 1584 (MO); forêt d'Angiritso, 24°49′36″S 47°08′37″E, 26 m, 10.IX.2012, fr., Ludovic 1697 (MO); forêt d'Ankatafamamy, 24°54′17″S 47°07′01″E, 20 m, 14.IX.2012, fr., Ludovic 1744 (MO); forêt d'Ambatomena, 24°49′36″S 47°08′37″E, 26 m, 16.IX.2012, fr., Ludovic 1763 (MO); Ste. Luce, 24°46′S 47°09′E, 10 m, 20.X.1989, fl., Rabevohitra 2056 (MO, P); Mahatalaky, 24°50′19″S 47°08′14″E, 6 m, 8.VIII.2012, fl., Rakotonirina et al. 881 (MO); Sainte Luce, Malailay be, 24°50′09″S 47°08′12″E, 6 m, 7.VIII.2012, fl., Ramananjanahary et al. 686 (MO); Mandromondromotra, Site IV, 24°55′22″S 47°01′30″E, 62 m, 18.VI.1997, fl. & fr., Ramison & Armand 313 (MO); Ampasy Nahampoana, forêt Omega, 24°57′52″S 47°00′13″E, 22 m, 24.VIII.2013, fr., Randrianaivo et al. 2364 (G, MO); Mandena, 24°57′08″S 47°00′11″E, 96 m, 12.VI.1999, fl., Randriatafika 61 (MO, P); Tapatany, 3 km E de Belavenoka, 24°52′21″S 47°07′21″E, 50 m, 4.VIII.2012, fl., Ratovoson 1901 (MO); Mandena, 24°57′S 47°00′E, 0 m, 22.VI.1996, fl., Razafimandimbison 220 (G, K, MO, P); Mahatalaky, Belavenoky, 24°51′29″S 47°07′12″E, 27 m, 9.VIII.2012, Razakamalala et al. 6914 (MO); Andohahela, Ifarantsa, 21.IV.1952, fl., Réserves Naturelles 3813 (P [2 sheets]); Ifarantsa, 26.V.1955, fl., Réserves Naturelles 7470 (P); Fenoro, Ifarantsa, 28.IV.1954, fl., Réserves Naturelles 7471 (P); Enaniliha, Fort-Dauphin, 8.I.1956, fl., Réserves Naturelles 8537 (P); forêt de Mandena, 17.IX.1950, fl., Service Forestier 1553 (P); ibid. loco, 12.VI.1952, fl., Service Forestier 5324 (P); ibid. loco, VIII.1953, fl., Service Forestier 7775 (P); ibid. loco, 24°57′S 47°02′E, 10 m, 22.V.1991, fl., Zarucchi et al. 7446 (MO, P). Reg. Vatovavy-Fitovinany [Prov. Fianarantsoa]: Ambodiramiavona, Mananjary, 17.VI.1954, fr., Service Forestier 14717 (P).

4. Homalium ihosyense Appleq., sp. nov. (Fig. 4).

Holotypus: Madagascar. Reg. Ihorombe [Prov. Fianarantsoa]: Vallée de la Menarahaka, à l'E d'Ihosy, II.1955, fl., Service Forestier 11627 (P [P04679113]!; iso-: P [P04679040]!]).

Homalium ihosyense Appleq. differs from H. analavelonae Appleq. in having thick-textured, usually elliptical leaves, longer racemes with peduncle very reduced, rachis pilose to glabrate, pedicels often longer (0.5–4.5 mm vs. 1–2 mm), and filaments longer (1.3–1.7 mm vs. 0.6–0.8 mm).

Tree to 8 m tall; twigs dark brown when young, becoming gray, glabrous. Leaves elliptical (to somewhat obovate or broadly elliptical), (4.7–)6.7–14 × (3–)4–6.3 cm, thick-textured; margin inconspiculously crenulate; base convex to rounded; apex cuspidate to short-acuminate (obtuse, rounded); both surfaces glabrous, drying greenish (the upper surface sometimes mottled) to grayish (dark brown); secondary veins slightly prominent; petiole 13–30 mm, glabrous. Inflorescences racemose, (3–)4.5–11 cm; peduncle virtually absent; rachis moderately pilose to glabrate; flowers 2–3 per node; pedicels 0.5–4.5 mm, short-pilose. Flowers 5-merous, white; sepals narrowly oblong, 1.8–3 mm, sparsely pilose outside, margins ciliate; sepal glands broadly elliptical, c. 0.6 × 0.5 mm; calyx cup sparsely pilose; petals oblanceolate, 3.5–12 mm, strongly accrescent, sparsely soft-pubescent to sparsely pilose on both surfaces, margins ciliate; filaments 1.3–1.7 mm; anthers broadly elliptical, 0.3 mm high.

Vernacular names. – “Sely” (Service Forestier 13729); “Tratramborondreo” (Service Forestier 13788).

Distribution, ecology and conservation status. – Homalium ihosyense is (or was) endemic to the valley of the Menarahaka near Ihosy (Fig. 2); it was reported to occur in mid-elevation dry forest on sand. The single known population has not been recollected for several decades. The large majority of the native vegetation in this area was unprotected and has been lost since the historical collections were made. This species is certainly to be assessed as “Critically Endangered” [CR B1ab(iii)+B2ab(iii)], if indeed it is not “Extinct in the wild”.

Notes. – Homalium ihosyense belongs to a group of species including H. albiflorum and H. analavelonae. It is most similar to the latter, which is likewise endemic to a small region of southern Madagascar. Though H. analavelonae is poorly known, it appears to have often broadly elliptical or broadly obovate leaves with usually rounded bases and proportionately shorter petioles; its inflorescence has a short (to 0.6 cm) peduncle, a villous rachis, pedicels to 2 mm long, and long appressed rather than pilose pubescence on the sepals and petals. It may have smaller flowers and smaller sepal glands, but material is too limited to allow conclusions.

Paratypi. – Madagascar. Reg. Ihorombe [Prov. Fianarantsoa]: Haute vallée de la Menarahaka à l'E d'Ihosy, 700–800 m, 28.I & 10.IV.1955, fl., Humbert 28610 (G, P); ibid. loco, 28.I.1955, fl., Service Forestier 13729 (P); ibid. loco, 20.III.1955, ster., Service Forestier 13788 (P); bassin de la Menarahaka, près du carrefour des route d'Ihosy à Ivohibe et Iakora, 650 m, 10.II.1963, fl., Service Forestier 22629 (G, P [2 sheets]).

5. Homalium leucophloeum (Tul.) Baill. in Bull. Mens. Soc. Linn. Paris 1: 576. 1886.

= Nisa leucophloea Tul. in Ann. Sci. Nat., Bot. sér. 4, 8: 72. 1857. ≡ Homalium albiflorum var. leucophloeum (Tul.) Baill. ex H. Perrier in Mém. Mus. Natl. Hist. Nat. 13: 295. 1940.

Holotypus: Madagascar. Reg. Analamanga [Prov. Antananarivo]: env. de Tananarivo, 1840, fl., Goudot s.n. (G [G00018421] image seen; iso-: P [P04679197 fragment]!).

= Homalium tetramerum Baker in J. Bot. 20: 110. 1882. Holotypus: Madagascar: “Central Madagascar”, VIII.1880 [com.], fl., Parker s.n. (K [K000231485] image seen).

Tree to 15(–30) m tall, 40[–48] cm dbh; bark gray to black; twigs pale to grayish (dark) brown, glabrous. Leaves elliptical (ovate, narrowly elliptical), (4.3–)5.2–10(–12.4) × (1.6–)2.1–4.5 (–5.8) cm, moderately thick-textured; margin shallowly repand to subentire (entire); base convex to rounded (short-attenuate); apex short-acuminate to rounded-cuspidate (acute, rounded, emarginate); both surfaces glabrous, usually drying green at least abaxially (rarely brown), darker to blackish adaxially (rarely darker abaxially); secondary veins slightly prominent; petiole sometimes red, (6–)9–14(–27) mm, glabrous. Inflorescences racemose, (1.5–)5–10(–14) cm; peduncle 0.2–1.4(–2.2) cm; rachis glabrous; flowers (1)2–3 per node; flowers sessile (in Cours 5205 pedicels 0.5–1 mm, pubescent). Flowers 4(5)-merous, white to greenish or yellowish white; sepals oblong to broadly oblong, 1.4–2.3[–2.8] mm, glabrous except margins ciliate; sepal glands orbicular or nearly so, 0.5–0.8 × 0.5–0.8 mm; calyx cup short-pubescent (glabrous); petals narrowly obovate, 3–5.6(–6.7[–8]) mm, moderately accrescent, glabrous, margins not ciliate [rarely sparsely short-ciliate]; filaments 1–1.4 mm; anthers broadly elliptical, 0.3 mm high.

Vernacular names and uses. – “Bemahova” (Andrianjafy et al. 1313); “Fandrianakanga” (Service Forestier 2243); “Hazoambo” (Service Forestier 2243); “Hazoambou” (Campenon s.n.); “Hazomainty” (Alleizette 1214); “Hazombato” (Lehavana et al. 257, Ursch 164a, 164b); “Hazomby” (Decary 6243, Parker s.n., Perrier de la Bâthie 6707, 6708, 6709); “Taimboalavo” (Cours 5205); “Zahana à grandes feuilles” (Service Forestier 15063).

Wood is reported to be hard but easy to work, used for construction and for heating and charcoal production (Cours 5205, Service Forestier 16187). An unspecified preparation of the plant is reported to be used to calm the stomach and as a diuretic (Alleizette 1214).

Distribution, ecology and conservation status. – Homalium leucophloeum is native to southeastern to northern humid forests, at least usually mid-elevation to high-elevation, and forests of the central plateau (Fig. 2). It has been reported on limestone, marble, and rocky substrate. It is known from over 10 historical populations, including several protected areas (Itremo, Ankafobe, Ankaratra-Manjakatompo, Andringitra, possibly Midongy du Sud and Montagne d'Ambre). Its conservation status is therefore assessed as “Least Concern” [LC]. However, it is of concern that recent collections are so few in number, perhaps because of past exploitation for wood.

Notes. – Homalium leucophloeum was accepted by Sleumer (1973) as a variety of H. albiflorum but is herein reinstated as a species. As for several other segregate species, it is differentiated from H. albiflorum s.s. by its usually 4-merous flowers with glabrous sepal and petal surfaces. Additionally, H. albiflorum has often larger, thin-textured leaves and the flowers are short-pedicellate; its distribution is northern and western, and it occurs at lower altitudes.

The few specimens from the extreme north (DIANA and SAVA regions) have relatively large elliptical, greenish, subentire leaves, sparsely ciliate petals, and in one case larger flowers than any other specimen (extremes of ranges marked with brackets above). These specimens are the only ones in this species or the group of related species that have ciliate petals, and the possibility that they are distinct or, contrarily, reflect some small degree of gene flow from H. albiflorum should be considered. One collection from very high altitude in the southeastern part of the distribution (Rogers 675) is of unusual appearance, with narrow, very long-petioled leaves and numerous racemes; this population may also be genetically distinct.

The isotype at P is marked “Emirna” [Imerina] and gives a date of February 1840, rather than just 1840. Its fragmentary nature strongly suggests that it is a duplicate of the holotype, but the inconsistency of labeling may make this uncertain.

Baron 5551, with modest-sized elliptical leaves, flowers paired in small bracts, glabrous petals, and ciliate sepals, has clear affinities to Homalium leucophloeum (or potentially H. baillonii). However, it also has 3 mm, relatively densely pubescent pedicels, an unexpected character in either of those eastern species. This is likely to be a hybrid, but the absence of any locality data hinders speculation regarding its parentage.

Additional material examined. – Madagascar. Reg. Amoron'i Mania [Prov. Fianarantsoa]: env. d'Ambatofitor[ah]ana au S d'Ambositra, 1500 m, VI.1912, fr., Perrier de la Bâthie 6710 (P); Itremo, Ambatofinandrahana, forêt d'Atsorakambiaty, 20°35′30″S 46°33′40″E, 1000 m, 7–8.III.1999, fl., Rabenantoandro et al. 68 (P). Reg. Analamanga [Prov. Antananarivo]: Parc de Tsimbazaza, 18°55′S 47°31′E, 13.II.1985, fr., Barnett et al. 460 (P); Km 26 de la route de Tamatave, 18.X.1951, fl., Benoist s.n. (P); Ambatovory, env. de Tananarive, IV.1957, fl., Bosser 11060 (MO, P); Carion [Nandihizana], 1100 m, 30.X.1927, fl., Decary 6026 (P); env. de Tananarive (Anosivato), 22.IV.1928, fr., Decary 6243 (MO, P); Ankazobe, forêt d'Ankafobe, 18°08′11″S 47°11′12″E, 1509 m, 23.II.2005, fl., Lehavana et al. 257 (G, K, MO, P); jardins et parcs à Tananarive, IV.1913, fl., Perrier de la Bâthie 6707 (P); Parc de Tananarive, IV.1913, fl., Perrier de la Bâthie 6708 (P); jardins et parcs à Tananarive, IV.1913, fl. & fr., Perrier de la Bâthie 6709 (P); sommet du rocher d'Ambatovory, distr. de Tananarive, 16.IV.1949, fl., Service Forestier 610 (P). Reg. Atsimo-Atsianana [Prov. Fianarantsoa]: Midongy du Sud, 2 km S du village de Beharena II, 23°32′23″S 47°05′07″E, 584 m, 16.IX.2005, fl., Andrianjafy et al. 1313 (MO); massif de l'Ivakoany, montagne Analanavelo, s.d., fr., Cours 5205 (P); village le plus proche Vohilava, Ambomindriha, 13.IV.1956, fl., Service Forestier 16187 (P). Reg. DIANA [Prov. Antsiranana]: E de la forêt d'Ambre, IX.1926, fr., Perrier de la Bâthie 17699 (P); forêt d'Ambavahibe, IX.s.a., fr., Ursch 164a (G, P); forêt d'Analamera, s.d., fr., Ursch 164b (P). Reg. Haute Matsiatra [Prov. Fianarantsoa]: Sud-Betsiléo, “wald von Ankafina”, II.1881, fl., Hildebrandt 3928 (G, P); Andringitra National Park, 22°09′19″S 46°56′41″E, 1750 m, 26.V.2004, fr., Rogers 675 (G, MO). Reg. Ihorombe [Prov. Fianarantsoa]: Melohavary, Farafangana, 23.V.1950, fl., Service Forestier 2243 (P). Reg. SAVA [Antsiranana]: Ampahana, Antalaha, 7.IX.1955, fr., Service Forestier 15063 (P). Reg. Vakinankaratra [Prov. Antananarivo]: Versant E du massif de l'Ankaratra, forêt de Manjakatompo, 24–26.III.1958, fl., Service Forestier 18503 (P). Reg. Vatovavy-Fitovinany [Prov. Fianarantsoa]: Ambakobe, 1100–1200 m, 9.VI.1881, fl., Lantz s.n. (P); Manakara, s.d., buds, Service Forestier 2738 (P). Reg. unknown: Imerina Nord, Ambohitraza, s.d., fl., Campenon s.n. (P); Tsarinandriano, VII.1906, fr., Alleizette 1214 (P); sine loco, s.d., fl., Baron 858 (P).

Specimen incertae sedis. – Madagascar: sine loco, s.d., fr., Baron 5551 (P).

6. Homalium megaphyllum Appleq., sp. nov. (Fig. 5).

Holotypus: Madagascar. Reg. DIANA [Prov. Antsiranana]: Behefaka, Anjahana, 13°21′32″S 49°10′10″E, 123 m, 5.VI.2005, fr., Hong-Wa et al. 296 (MO-6175072!; iso-: G [G00341931] image seen, P [P04734804]!, TAN).

Homalium megaphyllum Appleq. differs from H. leucophloeum (Tul.) Baill. in its much larger, usually elliptical to oblong-elliptical leaves with usually subentire margins, inflorescences often cauliflorous on twigs below leaves, and flowers often short-pedicellate.

Tree to 20 m tall, 30 cm dbh; twigs dark brown, glabrous. Leaves elliptical to oblong-elliptical (narrowly elliptical, ovate), 13–35 × (5–)5.7–11.5 cm, relatively thin-textured (moderately thick); margin subentire, often slightly undulate; base rounded to convex or somewhat oblique; apex cuspidate to short-acuminate or acute (rounded, emarginate); both surfaces glabrous, drying brown or green abaxially, dark brown to blackish (seldom greenish) adaxially; secondary veins slightly prominent; petiole sometimes red, (11–)13–20(–29) mm, glabrous. Inflorescences often mostly cauliflorous on twigs below leaves, racemose, (4.5–)8–15(–23) cm; peduncle 0.3–1.3(–3) cm; rachis glabrous (short-pubescent); flowers (1)2–4 per node; pedicels 0.5–1 mm, short-pubescent, or flowers sessile. Flowers 4-merous, white; sepals oblong to somewhat obovate, 1.3–3.5 mm, glabrous except margins short-ciliate; sepal glands suborbicular, 0.5–0.6 × 0.5 mm; calyx cup sparsely pubescent; petals narrowly obovate, 3.5–7 mm, moderately accrescent, glabrous, margins not ciliate; filaments 0.6–0.9 mm; anthers transversely elliptical, c. 0.3 mm high.

Etymology. – Homalium megaphyllum is so named for its exceptionally large leaves.

Vernacular names. – “Hazoadala” (Antilahimena et al. 370, 463, Gautier & Be 2905, Réserves Naturelles 1449, 2954, 4362, Service Forestier 7690, 9293, 13388); “Hazoanolalana” (Service Forestier 3054).

Distribution, ecology and conservation status. – Homalium megaphyllum is confined to northern Madagascar, primarily the DIANA region (Fig. 2). It is frequently reported to occur along the banks of rivers or streams, including seasonal temporary streams, and once to grow in deep red soil. It has been collected in degraded, or secondary, savoka forests. More than ten probably distinct populations have been collected, and it occurs in the protected areas of Manongarivo, Tsaratanana and Lokobe. Its conservation status is tentatively assessed as “Least Concern” [LC].

Notes. – Homalium megaphyllum is certainly more closely related to H. leucophloeum and H. baillonii than to H. albiflorum s.str., as evidenced by its 4-merous flowers with glabrous sepal and petal surfaces. It has a much larger maximum leaf size than any other species of the section, and is also unique in having most inflorescences borne proximally on mature twigs, rather than in leaf axils.

Paratypi. – Madagascar. Reg. DIANA [Prov. Antsiranana]: Ambato classified forest, river Bevoay, trail to Ankarefo, 13°28′03″S 48°32′22″E, 0–100 m, 28.V.1998, fl., Antilahimena et al. 370 (G, K, MO, P); Tsaratanana Massif, Antsahabe-Mandrizavona, 13°43′12″S–13°48′S 48°39′25″E–48°45′E, 150–750 m, 12.IV.2000, fl., Antilahimena et al. 463 (BR, G, K, MO, P); env. de Maromandia (Kapany), 9.IV.1923, fl., Decary 1676 (G, P); Besinkara, 14°04′S 48°17′E, ch. d'Ambalafary à Ambodisakoana, 350 m, 26.III.1996, fl., Gautier & Be 2905 (G, MO, P); SW d'Ambilobe, 10 m, III.1951, fr., Humbert & Capuron 25589 (P); Vallée de l'Ifasy en aval d'Anaborano, distr. d'Ambilobe Nord, 50–200 m, 31.III.1951, fr., Humbert & Capuron 25880 (P); env. de Mt. Bekolosy, massif de Manongarivo, III.1909, fl. & fr., Perrier de la Bâthie 6718 (P [2 sheets]); presqu'île d'Ampasindava, 13°46′30″S 48°05′35″E, 215 m, 7.V.2012, fr., Rasoanaivo & Tahinarivony 28 (MO); Tsaratanana, rive droite du Sambirano, au delà du village Beangona, 21.V.1948, fr., Réserves Naturelles 1449 (P [3 sheets]); Lokobe, Nossi Be, 22.IX.1952, fl., Réserves Naturelles 4362 (P [2 sheets]); Andrahibo, Ambanja, 16–30.III.1951, fl., Service Forestier 2954 (P); entre Ambatobe et [illegible], distr. d'Ambilobe, 12.III.1951, fl., Service Forestier 3054 (P); Benavony, Ambanja, 25.III.1954, fr., Service Forestier 9293 (P); Manongarivo RS, Anketraka Be, Bas Ambahatra, cours inférieur du bassin-versant de rano Ambahatra (13°55′16″S, 48°27′47″E), 180 m, 22.VII.1998, fr., Wohlhauser & Andrianjaka 60016 (G, MO, P). Reg. Sofia [Prov. Mahajanga]: Analalava, Bekaraka, env. 40 km S d'Ambanja le long de la RN6, 13°56′09″S 48°12′45″E, 195 m, 21.V.2006, fl., Rakotoarisoa & Andriamahay 436 (MO); Ambodisaina, Ambanja, 17.IX.1953, fr., Service Forestier 7690 (P); Ampondralava, Antsohihy, 25.IV.1955, fr., Service Forestier 13388 (P). Reg. unknown: sine loco, s.d., fr., Baron 6224 (P).

7. Homalium phillipsonii Appleq., sp. nov. (Fig. 6).

Holotypus: Madagascar. Reg. Atsimo-Atsinanana [Prov. Toliara]: near Sakaraha, forêt de Zombitsy, 22°52′S 44°31′E, 750 m, 6.I.1989, fl., Phillipson 3095 (MO-3762461!; iso-: G [G00341926] image seen, P [P04679124]!, TAN).

Homalium phillipsonii Appleq. differs from H. albiflorum (Boivin ex Tul.) O. Hoffm. in having pilose indument on all parts, leaves sometimes narrower, with strongly prominent secondary veins, sometimes with apparent small domatia in axils, and often asymmetrical apices, and larger anthers.

Tree to 15 m tall or shrub; bark caducous in plaques; twigs pale (dark) brown when young, becoming dark to grayish, pilose. Leaves elliptical to obovate, oblong-elliptical or narrowly elliptical (to oblanceolate), (4–)5.5–14 × (1.8–)2.4–6 cm, relatively thin-textured; margin shallowly crenate to crenate-serrulate; base convex (to rounded); apex short-acuminate to cuspidate (long-acuminate), often asymmetrical at tip, to acute (obtuse, emarginate, rounded-obtuse); both surfaces pilose especially over veins, more sparsely short-pilose adaxially, drying green or brown, the adaxial surface darker (seldom dark grayish); secondary veins strongly prominent, sometimes apparently with small domatia in axils; petiole sometimes red, (5–)7–14 mm, pilose. Inflorescences racemose, (2.5–)5–12(–16.5) cm; peduncle 1–3.5 cm; rachis short-pilose; flowers 2–3(4) per node; pedicels 0.5–2 mm, pilose. Flowers 5-merous, white; sepals obovate-oblong to oblong-elliptical or narrowly oblong, 0.9–2.4 mm, short-pilose to appressed-pubescent on outer surface and apical part of inner surface, margins ciliate; sepal glands broadly elliptical (orbicular), 0.4–0.7(–0.8) × 0.4–0.6 mm; calyx cup pilose; petals obovate with a narrowed base to oblanceolate, 1.5–8 mm, strongly accrescent, sparsely short-pubescent on both surfaces, margins ciliate; filaments 0.7–1 mm; anthers broadly elliptical, 0.35 mm high.

Etymology. – Homalium phillipsonii is named for Peter B. Phillipson, collector of the type, to honor his many contributions to the botany of Madagascar.

Vernacular names. – “Lalimpitonala” (Service Forestier 4570); “Lalipitonala” (Service Forestier 4989); “Lalipitonantro” [?] (Service Forestier 3401); “Lalipotonala” (Service Forestier 2818).

Distribution, ecology and conservation status. – Homalium phillipsonii as herein described is native to the Atsimo-Andrefana region of southwestern Madagascar (Fig. 2). [As noted below, there are similar populations in northern Madagascar, but the status of these is doubtful]. It occurs in dry deciduous forest and bush, on sand and rocky limestone substrates. Based on historical collections, the EOO is estimated as 11,806 km2, and the AOO as 72 km2. It appears that more than ten distinct populations have existed. However, in recent decades all collections but one (Razakamalala 6111) have been made in the protected area of Zombitsy. The vast majority of the habitat is unprotected, has suffered severe damage since the time when historical collections were made (with all woody species suitable for use as charcoal virtually extirpated in many areas), and continues to be subject to ongoing anthropogenic damage. Therefore, it is considered very likely that some of the historical populations are now extinct, and that the species should be assessed as “Vulnerable” [VU B2ab(iii)].

Notes. – Homalium phillipsonii is most readily distinguished from H. albiflorum s.str. by the pilose indument of its leaves, twigs, petioles, and portions of the calyx. In H. albiflorum, the pedicels and calyx are occasionally pilose but the leaves, twigs, and petioles, though rarely pubescent, are not pilose. Homalium phillipsonii has more strongly prominent secondary veins than any related species, and more frequently has small structures interpreted as domatia. The inflorescences also seem subjectively to appear thicker and less pendent than those of H. albiflorum, and the anthers are larger and narrower than usual for that species (whose morphology is variable).

A few specimens that key out as H. phillipsonii, noted below as “incertae sedis”, are from much farther north, even from the extreme north. There are no specimens of H. phillipsonii known from the intervening regions, so if those populations were H. phillipsonii the species would have a highly disjunct distribution.These sometimes have a sparser indument on various parts than typical H. phillipsonii and might be viewed as transitional forms between H. phillipsonii and H. albiflorum, which does occur in that range. However, material of H. albiflorum from the southernmost portion of the distribution of that species (the regions of Menabe and Melaky) does not appear to intergrade with H. phillipsonii, farther to the south, at all. It is therefore questionable whether gene flow between the species is possible. The northern populations may well be genetically distinct, although they are not strongly distinguished morphologically; further collections from the region might help to resolve their status.

Paratypi. – Madagascar. Reg. Atsimo-Andrefana [Prov. Toliara]: Manasoa Tanosy, 11.I.1913, fl., Afzelius s.n. (MO [2 sheets], P); Andoharanomaitso, Parc de Zombitse, partie SE, 22°54′22″S 44°40′22″E, 800 m, 25.XII.2004, fl., Andriamihajarivo et al. 540 (MO); Parc National de Zombitse, NW du village de dika, lieu dit Poakafo, 22°46′09″S 44°40′15″E, 531 m, 10.IV.2006, fr., Andriamihajarivo et al. 921 (MO, P); Sakaraha, II.1956, fl., Bosser 9111 (MO, P); Tsarasao S de Sakaraha, 14.II.1970, fl., Bosser 19913 (P); Baie de St. Augustin (Tulear), 8.II.1957, fl., Descoings 2406 (MO); Basse vallée du Fiherenana, 50–200 m, XI.1933, fl., Humbert 11557 (G, P [2 sheets]); Bassin moyen du Fiherenana entre Lambomakandro et Sakaraha, 400 m, 10.XII.1946, fl., Humbert 19683 (G, P); Gorges du Fiherenana entre Beantsy et Anjamala, 30–300 m, 16–19.I.1947, fl., Humbert 19920 (P); Plateau au S des gorges du Fiherenana entre Andranohinaly et Andranovory, 300–400 m, 3–4.II.1947, fl., Humbert 20112 (P); forêt de Zombitsy (entre Ranohira et Sakaraha), III.1960, fl., Keraudren 484 (P [2 sheets]); 20 km S de Sakaraha, Tsaramasao, III.1970, fl., Morat 3503 (MO, P [6 sheets]); Zombitsy, 1 km N du village d'Andranomaintso, 22°53′23″S 44°38′36″E, 600–700 m, 3.II.1999, fr., Randrianaivo et al. 312 (MO, P); Fkt. Betorabato, Ambalamanga, forêt Akolitsika, 21°40′22″S 44°59′36″E, 286 m, 21.I.2011, fl., Razakamalala 6111 (MO); rte Tulear Sakaraha, 23.II.1949, fl., Service Forestier 517 (P); Analamary, Sakaraha, 22.I.1951, ster., Service Forestier 2818 (P); Andranovory, Tuléar, 19.III.1951, fr., Service Forestier 3401 (P); Lambomakandro, Tuléar, 23.I.1953, fl., Service Forestier 4570 (P); Soaserana, Sakaraha, 21.II.1952, fl., Service Forestier 4989 (P); forêt Anadabovalo, Ambohimahavelona, Tuléar, 27.I.1955, fl., Service Forestier 13064 (P); forêt d'Hera [Ihera], au N de Mitia dans le haut bassin de l'Ilona (au NE du massif de l'Analavelona), 600–700 m, 16.XII.1962, fl., Service Forestier 22216 (P).

Specimens incertae sedis: Madagascar. Reg. Boeny [Prov. Mahajanga]: Bemazava, près de l'embouchure de la Mahavavy (Ambongo), VI.1903, fl., Perrier de la Bâthie 2264 (P); forêt de Bekapika, sur le plateau d'Antanimena (Boina), 12–14.XI.1957, fl., Service Forestier 18432 (P). Reg. SAVA [Prov. Antsiranana]: Daraina, forêt de Ambilondomba, 13°09′S 49°38′E, 480 m, 27.I.2004, fl., Ranirison et al. 323 (MO, P). Reg. Sofia [Prov. Mahajanga]: distr. Analalava, forêt d'Ambondro-Ampasy (Exploitation Loyseau), 29.X–3.XI.1958, fl., Service Forestier 18835 (MO, P).

8. Homalium pseudoracemosum Appleq., sp. nov. (Fig. 7).

Holotypus: Madagascar. Reg. Sofia [ Prov. Mahajanga]: forêt de Betsitindry, Ambato, distr. Befandriana, 24.X.1956, fr., Service Forestier 16408 (MO-2818801!; iso-: P [P04679193]!).

Homalium pseudoracemosum Appleq. differs from H. albiflorum (Boivin ex Tul.) O. Hoffm. in having usually mostly lanceolate to ovate leaves, consistently short-branched racemiform panicles with glabrous or glabrate rachises, and flowers smaller, usually 4-merous, with petals glabrous except margins sometimes sparsely ciliate.

Tree to 20 m tall, 38 cm dbh; twigs dark brown later becoming pale brown, glabrous. Leaves lanceolate to ovate, narrowly elliptical, or elliptical, (4.8–)6–13.5(–14) × 2.4–5.5(–5.8) cm, thin-textured; margin irregularly crenulate (to crenate-serrulate) or subentire; base convex (often short-attenuate at extreme base); apex short-acuminate (to acute, rounded, or obtuse); both surfaces glabrous, drying brown, often darker (to blackish) adaxially (rarely greenish adaxially); secondary veins slightly prominent; petiole (7–)9–14(–17) mm, glabrous. Inflorescences short-branched paniculate, (3.5–)6–13.5 cm; peduncle 0.7–3.5 cm; rachis glabrous or glabrate (branches sometimes sparsely minutely pubescent); flowers mostly in clusters of 2–4(–5), many or most clusters borne on small inconspicuous branches; pedicels 0.5–3 mm, short-pubescent. Flowers 4(5)-merous, greenish to yellow; sepals oblong to broadly ovate (suborbicular), (1.3–)1.5–2.5 mm, sparsely pubescent outside or glabrous, margins ciliate; sepal glands broadly elliptical, 0.6–0.8(–1) × 0.5–0.7 mm; calyx cup sparsely short-pubescent; petals obovate, 3–5.5 mm, little accrescent, glabrous except margins sometimes sparsely short-ciliate; filaments 1–1.5 mm; anthers broadly elliptical (to transversely elliptical?), 0.2–0.3 mm high.

Etymology. – Homalium pseudoracemosum is so named because its inflorescences appear on casual observation to be racemose, but are actually paniculate.

Vernacular names and uses. – “Ampimba” (Reserves Naturelles 2137); “Apimba” [?] (Service Forestier 3994); “Ampiniba” (Reserves Naturelles 4229); “Hazoamboa” (Louvel 168); “Hazomby” (Service Forestier 3917); “Lalipito” (Service Forestier 4445); “Mampisaraka” (Service Forestier 7796); “Revy” (Service Forestier 10517); “Saripapy” (Service Forestier 10875); “Taindalitra” (Service Forestier 15143); “Trongindambo” (Service Forestier 12026, 26203 [Sakalava dialect]).

Wood is used for construction and manufacture of planks (Service Forestier 16408, 26203).

Distribution, ecology and conservation status. – Homalium pseudoracemosum has been widespread in the dry western regions of Madagascar, with a latitudinal range extending from Menabe to Sofia and possibly DIANA (Fig. 2).The two specimens from the DIANA region in the extreme north are atypical and are tentatively placed here.The species is reported to occur on limestone.

Homalium pseudoracemosum has probably occurred in more than ten populations, though locality data are poor in many cases, and in protected areas including the Bemaraha reserve, Namoroka, and (an atypical specimen) Montagne d'Ambre. Therefore, by standard application of the IUCN criteria, its conservation status would be assessed as “Least Concern”. However, the fact that only one atypical recent collection exists is of great concern. The case of this species may be compared to that of H. albiflorum, which has a similarly broad western-to-northern distribution, but has been collected from four regions since 1990. From historical data, the EOO of H. pseudoracemosum would be estimated as 140,994 km2 (including the DIANA populations) and the AOO as 72 km2. The vast majority of the potential habitat is unprotected and has been destroyed or severely degraded by human activity since the 1940s and 1950s, when most collections were made. As in the case of H. phillipsonii, it is probable that several of the historically collected populations no longer exist. Therefore, it is suggested that the conservation status of this species should be estimated as, minimally, “Vulnerable” [VU B2ab(iii)] because of the small AOO, presumably fewer than 10 surviving populations, and severe, continuing decline in area and quality of habitat.

Notes. – Homalium pseudoracemosum is distinguished by its short-branched racemiform panicles and lanceolate to ovate or elliptical leaves. Elliptical leaves (as on the atypical Andrianantoanina & Bezara 857) are often at the lower end of the size range, suggesting that they could be immature. The maximum size of the flowers appears to be smaller than in most species of this section, with the petals less strongly accrescent than most. This species occurs in much of the same range as H. albiflorum, which has usually elliptical leaves, usually racemose (though occasionally narrowly paniculate) inflorescences, pubescent rachises and flowers, and usually 5, somewhat larger petals. Homalium albiflorum is the only other species that ever has panicles of this form. The two are suspected to be closely related and to hybridize. However, H. pseudoracemosum also shows possible affinities to the H. leucophloeum group of mostly eastern species in its usually 4-merous, nearly glabrous sepals, petals, and inflorescences. Thus H. pseudoracemosum appears in some ways to represent an intermediate between these species groups.

Species of the H. albiflorum complex are generally described as having white or whitish flowers, when the color is reported, although H. leucophloeum is said to have pale greenish to pale yellowish flowers. Andrianantoanina & Bezara 857, one of the atypical extreme-northern specimens of H. pseudoracemosum, has label data reporting that the calyx is green and the corolla yellow. It is unclear whether this unusual report is due to life stage or differing interpretations of lightly pigmented petals, or whether this species indeed has a significantly different and darker flower color than most of its relatives. If the latter, it would provide another distinguishing feature in the field.

Several specimens appear morphologically intermediate between H. pseudoracemosum and H. albiflorum. Those from Ankarana have quite narrow leaves, inconsistently branched inflorescences with pubescent rachises, and pubescent flowers. Other narrow-leaved specimens possibly representing introgression between the two species are treated above under H. albiflorum. Leandri 356 was probably collected around the same time as Leandri 357, which is identified as H. albiflorum. This specimen has some features that are more consistent with H. pseudoracemosum, including sometimes narrow leaves, usually (but not always) glabrous rachises, and petals glabrous except for cilia. The bracts are cup-shaped and unusually large for either species (a feature also sometimes seen in the Ankarana specimens). No other possible parental species are known from near Bemaraha.

Paratypi. – Madagascar. Reg. Boeny [Prov. Mahajanga]: Plateau d'Ankara, VIII.1900, fr., Perrier de la Bâthie 1090 (P); Andrengy [Namoroka], Soalala, 21.I.1950, fl. & fr., Réserves Naturelles 2137 (G, P [2 sheets]); R.N. 8 [Namoroka], Andranomavo, Soalala, 5.VIII.1952, fr., Réserves Naturelles 4229 (P [2 sheets]); Belalanda, Soalala, 9.VIII.1951, fl., Service Forestier 3994 (P). Reg. DIANA [Prov. Antsiranana]: Montagne d'Ambre, 8 km E de Bobakilandy (Antsanavo), 12°37′37″S 49°06′40″E, 533 m, 11.VII.1995, fl., Andrianantoanina & Bezara 857 (BR, G, K, MO, P); Nosy Mitsio, X.1952, fr., Perrier de la Bâthie 18767 (P). Reg. Melaky [Prov. Mahajanga]: E du Bemaraha, VIII.1943, fr., Herb. Jard. Bot. [Cours] 6192 (P [2 sheets]); Antsingy, Antsalova, 29.X.1954, fr., Service Forestier 12096 (P); Antanimbaribe, Morafenobe, 6.VIII.1955, fr., Service Forestier 15143 (P); Forêt de Beandrao, Ankazomandiladongo, canton and distr. Antsalova, 23.IX.1966, fr., Service Forestier 26203 (P). Reg. Menabe [Prov. Toliara]: Bassin de la Tsiribihina au N de Morondava, s.d., fl., Louvel 168 (P); Dabora, Morondava, 18.VIII.1951, fr., Service Forestier 3917 (P); Marofototra, Marovoay, Morondava, 15.XII.1951, fr., Service Forestier 4445 (P); Ankilimidahy, Belo/Tsiribihina, 1.VII.1953, fr., Service Forestier 7796 (P); Torrent à une trentaine de km à l'W du Betafo, sur la route de Miandrivazo, 26.VIII.1953, fl., Service Forestier 8429 (P); Ankilizato, distr. de Mahabo, 26.VI.1954, fl., Service Forestier 10517 (P); forêt d'Antabefotsy, Ankazomanga, Miandrivazo, 14.IX.1954, fr., Service Forestier 10875 (P).

Possible hybrid specimens. – Madagascar. Reg. DIANA [Prov. Antsiranana]: Ankarana RS, N of Ambilobe, 12°56′S 49°07′E, 100–300 m, 20.III.1993, fl., Andrianantoanina & Du Puy 27 (MO); Ankarana, Sentier Botanique, 17 km NE de Mahamasina, 12°50′47″S 49°06′18″E, 82 m, 17.I.2002, fl., De Block et al. 1277 (G, MO). Reg. Melaky [Prov. Mahajanga]: Tsingy du Bemaraha (9e Réserve), 1932–1933, fl., Leandri 356 (MO, P [3 sheets]).

9. Homalium rakotovaoi Appleq., sp. nov. (Fig. 8).

Holotypus: Madagascar. Reg. SAVA [Prov. Antsiranana]: Andapa,Doany,Andranomilolo,env.13 km à l'W d'Andranopositra, 14°19′44″S 49°16′57″E, 841 m, 2.XI.2006, fr., Rakotovao et al. 3228 (MO-6175072!; iso-: G [G00341925] image seen,MO-6175714!,P [P05529033]!, TAN).

Homalium rakotovaoi Appleq. differs from H. leucophloeum (Tul.) Baill. in its often larger, ovate leaves with crenate to crenulate, often revolute margins, racemes with (1–)3–7 flowers per node, and well-developed pedicels.

Tree to 25 m tall or shrub; twigs dark brown with conspicuous pale lenticels, glabrous. Leaves ovate (lanceolate to elliptical), (5.5–)6.7–15.7 × (2.8–)3.5–6.5 cm, variably thickish to thin-textured; margin irregularly and shallowly crenate to crenulate (sometimes slightly undulate), often somewhat revolute; base rounded (often minutely attenuate at petiole junction) to convex, slightly oblique (very broadly cuneate); apex acuminate (acute, obtuse, or emarginate); both surfaces glabrous, drying brown to greenish, the upper surface usually brown, darker; secondary veins very little prominent; petiole sometimes (but not consistently) red, 9–16(–22) mm, glabrous. Inflorescences racemose, (3–)5–16 cm; peduncle 0.3–1.2(–2.7) cm; rachis glabrous (sparsely pubescent); flowers (1–)3–7 per node; pedicels (1.5–)2.5–6(–8.5) mm, moderately pubescent. Flowers 4-merous, white; sepals oblong (slightly obovate), 1.4–2.2 mm, glabrous or glabrate, margins not ciliate; sepal glands broadly elliptical (orbicular), 0.4–0.6 × 0.3–0.4 mm; calyx cup sparsely pubescent; petals obovate, 2.7–6.2 mm, glabrous, margins not ciliate; filaments 0.8–1.5 mm; anthers broadly elliptical, 0.3 mm high.

Etymology. – Homalium rakotovaoi is named for Charles Rakotovao, collector of the type, to honor his many contributions to botany in Madagascar.

Vernacular names. – “Azoadala” (Reserves Naturelles 6017); “Hazoadala” (Randrianarivelo et al. 442, Saboureau s.n., Service Forestier 9280); “Hazoadala (p.[etites] f.[euilles])” (Reserves Naturelles 4182); “Janganita fotsy” (Reserves Naturelles 1751); “Malazovoavy” (Decary 1030).

Distribution, ecology and conservation status. – Homalium rakotovaoi is native to northern Madagascar (Fig. 2). It has been reported to occur in mid-altitude humid forest (though much of the potential range is probably subhumid) and to occur near rivers or on slopes, once on limestone. The EOO is estimated as 3434 km2, and the AOO as 36 km2, with some collections' localities estimated with a low degree of accuracy, but with fewer than ten distinct populations known. Several collections are from various portions of the protected area of Tsaratanana. The conservation status is tentatively estimated as “Least Concern” [LC].

Notes. – Homalium rakotovaoi has usually ovate leaves with often conspicuously crenate to wavy (though sometimes subentire) margins, large clusters of long-pedicellate flowers, narrow acute sepals, and 4-merous flowers that are glabrous or glabrate except for sparse pubescence on the calyx cup, the sepals and petals without ciliate margins. The latter floral characters indicate a closer relationship to the H. leucophloeum group than to H. albiflorum s.s. Most of the species in that group have usually more or less elliptical leaves with often entire margins and flowers in groups of up to 3 or 4, with short pedicels or sessile. Two species, H. rakotovaoi and H. vohitsiandrianense Appleq. (see below), have usually ovate leaves, well-developed pedicels, and flowers sometimes in larger groups (in this species, at the extreme, up to 7). They are presumed to be sister species. Homalium vohitsiandrianense, which is known only from a southeastern massif, has smaller, sometimes broadly ovate leaves with usually acute apices, shorter racemes, and huge sepal glands.

Ranirison & Nusbaumer 914 has large (to over 15 cm long, 8 cm broad), glabrous leaves with often acuminate apices and flowers in clusters of several with well-developed pedicels. However, the leaves are elliptical and it has long-peduncled pubescent inflorescences and large pentamerous flowers with pilose calyces (with unusually long narrow sepals) and pubescent petals. It is plausibly interpreted as a hybrid of H. rakotovaoi and H. albiflorum. Although H. rakotovaoi has not been collected near Daraina, its presence in that region is predicted based on the existence of this intermediate. However, an alternative possibility is that this collection is a distinct, locally endemic species that happens by coincidence to have intermediate morphology. Further collections from Daraina would be desirable.

Paratypi. – Madagascar. Reg. DIANA [Prov. Antsiranana]: Tsaratanana, Antsahabe riv, 14°00′45″S 48°46′40″E, 700–1200 m, 27.VII.2000, fl., Antilahimena et al. 506 (BR, K, MO, P); Tsaratanana Massif, path from Mahatsabory Mica and Mangindrano, W of Befosa River, 14°12′22″S 48°57′14″E, 1400 m, 21.X.2001, fl. & fr., Birkinshaw et al. 993 (G, MO, P); env. de Mt. Tsaratanana, 1700 m, XI.1912, fr., Perrier de la Bâthie 6703 (P); ibid. loc., 1500 m, XI.1912, fr., Perrier de la Bâthie 6704 (P); 10 km NE de Mangindrano, forêt d'Antsahivo, 14°14′34″S 49°00′31″E, 1249 m, 29.XI.2005, fr., Randrianarivelo et al. 442 (MO, P, G); Marovato, Ambanja, 28.IX.1948 or 29.VIII.1948, fl., Réserves Naturelles 1751 (P [2 sheets]); ibid. loco, 19.VII.1952, fl., Réserves Naturelles 4182 (P [2 sheets]); Andavaka, Ambanja, s.d., fl., Saboureau s.n. (P); Andavaka, 20.X.1949, fl., Service Forestier s.n. (Rakoto 6) (MO). Reg. SAVA [Prov. Antsiranana]: Ampoanaomby [Amponaomby], Andapa, 3.XII.1953, fl. & fr., Service Forestier 9280 (P, G). Reg. Sofia [Prov. Mahajanga]: Maromandia (Bemaneviky), 23.IX.1922, fl., Decary 1030 (P); 7 km NE Mangindrano près de la rivière Antsahivo, 14°14′27″S 49°00′18″E, 1233 m, XI.2005, fr., Rakotovao & Jaovazaha 2628 (MO, P); Tsaratanana, sommet, 1.VII.1953, fl., Réserves Naturelles 6017 (P).

Probable hybrid specimen. – Madagascar. Reg. SAVA [Prov. Antsiranana]: Daraina, forêt de Bobankora, 13°13′36″S 49°45′31″E, 320 m, 26.I.2005, fl., Ranirison & Nusbaumer 914 (G, MO, P, TEF).

10. Homalium rubriflorum Sleumer in Bull. Jard. Bot. Natl. Belg. 43: 302. 1973.

Lectotypus (designated here): Madagascar. Reg. Alaotra-Mangoro [Prov. Toamasina]: Analamazaotra, Perinet, 9.III.1954, fl., Service Forestier 8365 (P [P00375175]!; isolecto-: G [G00341927] image seen, L [L0011009] image seen, MO-2818814!, P[P04734390, P04734382]!, PRE [PRE0594538-0] image seen, TEF [TEF000234] image seen).

Tree to 35 m tall, 80 cm dbh; bark reddish, caducous in plaques; twigs light brown, minutely pubescent to glabrous. Leaves elliptical to broadly (narrowly) elliptical, (4.5–)5.5–16 × 2.1–5.5(–8) cm, thin-textured; margin subentire, often slightly undulate, to crenulate-serrulate; base convex (rounded); apex acuminate to cuspidate (acute, obtuse, rounded or emarginate); both surfaces glabrous (seldom sparsely appressed-pubescent, mostly on midrib abaxially), drying brown abaxially, dark brown to blackish adaxially (rarely greenish); secondary veins slightly prominent; petiole 4–8(–10) mm, glabrous (sparsely minutely pubescent). Inflorescences sometimes partly terminal, long-branched peduncles (reduced to racemes), (3.7–)6–16(–20) cm; peduncle 0.6–2.4(–3.2) cm; rachis short-pubescent; flowers 1–2 per node; pedicels (1–)1.4–3(–5) mm, short-pubescent (sometimes densely). Flowers 5-merous, red; sepals oblong-ovate to oblong, 0.7–1.3 mm, sparsely appressed-pubescent outside, margins minutely ciliate; sepal glands irregularly broadly elliptical, 0.3–0.5 × 0.3 mm; calyx cup short-pubescent; petals obovate, 2.4–4 mm, little accrescent, sparsely appressed-pubescent on outer surface mostly towards base, margins ciliate; filaments 0.3–0.6 mm; anthers biglobose, c. 0.1 mm high.

Vernacular names. – “Zahana” (Cours 4437); “Zanahy” (Service Forestier 26); “Zandambo” (Service Forestier 9779, 28753).

The wood is reported to be very hard and used in construction (Cours 4437).

Distribution, ecology and conservation status. – Homalium rubriflorum is native to mid-elevation humid forests in the Alaotra-Mangoro region of northeastern Madagascar. The EOO is estimated as 5612 km2, and the AOO as 32 km2. As few as four clearly distinct populations have been collected. Two of these, which supply almost all of the collections, have been widely distributed in the protected areas of Analamazaotra or Perinet (now Andasibe-Mantadia) and Zahamena. Therefore, the species is not expected currently to be experiencing severe declines in available habitat, and its conservation status is estimated as “Least Concern” [LC]. However, it is of concern that the only recent collections have been from a single area, that of Zahamena.

Notes. – Sleumer saw two duplicates of the type collection at P [P00375175, P04734390]. Both sheets were marked by Sleumer as “holotype”, but only the former is treated as a type by the Paris herbarium. Since Sleumer did not distinguish between these two sheets in labeling or in print, they are to be treated as syntypes (Art. 40, Note 1 of the ICN; Turland et al., 2018) and one should be chosen as lectotype. The sheet previously labeled as the type is herein designated as lectotype because it is a better specimen and has both the original collector's label and additional material in a fragment packet.

Additional material examined. – Madagascar. Reg. Alaotra-Mangoro [Prov.Toamasina]: d'Andasibe à Andapabe, 900 m, 16.III.1951, fl., Cours 4437 (P [2 sheets]); Ambatovola, I.1928, fl., Perrier de la Bâthie 18411 (P [2 sheets]); Parc National de Zahamena, Vohitsingitry, 17°39′31″S 48°39′20″E, 1085 m, 21.II.2000, fl. & fr., Rakotonandrasana et al. 401 (MO, P); Parc National de Zahamena, Ankosy, piste vers Bemoara, 17°28′58″S 48°44′10″E, 997 m, 14.VII.2000, fl., Rakotonandrasana et al. 420 (MO, P); Im[er]imandroso, Ambatondrazaka, 16.IV.1956, fl., Réserves Naturelles 8712 (P); Analamazaotra, s.d., fl. & fr., Service Forestier (Louvel) 26 (P); Ambatomasina, Antandrokomby, 15.III.1954, fl., Service Forestier 9779 (MO [2 sheets], P [2 sheets]); Versant W du Massif de l'Ampahana, à l'E de Fierenena (Moramanga), 950–1300 m, 10–16.III.1969, fl., Service Forestier 28753 (P [2 sheets]).

11. Homalium sanguineum (Boivin ex Tul.) Baill. in Bull. Mens. Soc. Linn. Paris 1: 575. 1886.

= Nisa sanguinea Boivin ex Tul. in Ann. Sci. Nat., Bot. sér. 4, 8: 70–71. 1857.

Lectotypus (designated here): Madagascar. Reg. Analanjirofo [Prov.Toamasina]: Ile Ste. Marie, bords de la mer un près de Tanambo [Tanambao], V.1847, fl. & fr., Boivin 1846 (P [P04734378]!; isolecto-: BM, G [G0001388, G0001389] images seen, L [L0011012 fragment] image seen, P [P04734379, P04734380 and attached sheet of fragments]!, W).

Tree to 20 m tall with main trunk to 12 m, dbh 25 cm; twigs pale gray, glabrous. Leaves broadly elliptical (elliptical, somewhat obovate), (5.6–)7.7–11.7 × (3.8–)4.2–8.2 cm, thin-textured; margin subentire; base broadly convex, at extreme base short-attenuate; apex rounded to emarginate or cuspidate; both surfaces glabrous, drying dark brown; secondary veins slightly prominent; petiole (9–)12–22 mm, glabrous. Inflorescences sometimes partly terminal, panicles with well-developed branches (partly reduced to racemes), (7.5–)10–24 cm; peduncle (1–)2.3–7(–15) cm; rachis short-pubescent distally; flowers 1 per node; flowers sessile. Flowers (4)5-merous, red; sepals narrowly oblong-ovate to ovate, 1.4–2.4 mm, sparsely short-pubescent outside, margins usually short-ciliate; sepal glands irregularly broadly elliptical, 0.5–0.6 × 0.4 mm; calyx cup sparsely short-pubescent; petals oblanceolate to obovate, 4.4–6.3 mm, probably accrescent, glabrous, margins sometimes sparsely and minutely ciliate; filaments c. 1.1–1.2 mm; anthers broadly elliptical, 0.3 mm high.

Vernacular names and uses. – “Hafotrantsotry vavy” (Raharimalala 269); “Tanatanam-potsy” (Antilahimena et al. 911, Rabehevitra 38).

Matière végétale”, presumably leaves, are used in the making of Malagasy rum (Rabehevitra 38).

Distribution, ecology and conservation status. – Homalium sanguineum is native to low-altitude humid forests in a small portion of northeastern Madagascar. Only three distinct populations have been collected, and the species appears to be rare. The EOO is estimated as 240 km2, and the AOO as 12 km2 (the three populations are clearly separated, but are arranged in almost a linear pattern, making the calculated EOO low). One collection was made in the protected area of Mananara-Nord. However, most of the habitat is unprotected and continues to suffer anthropogenic damage. Therefore, the estimated conservation status of this species is “Endangered” [EN B1ab(iii)+B2ab(iii)].

Notes. – The holotype of Nisa sanguinea has been reported to be at P (Sleumer, 1973: 301, with the collection number misstated as the year of collection). Since three sheets of the type collection are present at P and no distinction among them has been published, these are syntypes and one must be selected as lectotype. The sheet numbered P04734378 is by far the best, so is chosen here. Two un-numbered Boivin collections at P have been marked as probable or questionable type material, but their status is unclear, and the specimen said to have been cultivated outside Madagascar, in the botanical garden on the island of Bourbon, certainly is not type material.

Additional material examined. – Madagascar. Reg. Analanjirofo [Prov. Toamasina]: Fkt. Rantabe, 15°42′39″S 49°37′39″E, 24.II.2002, fl., Antilahimena et al. 911 (MO); rte entre Rantabe et Morafeno, 15°42′39″S 49°37′51″E, 24–25.II.2002, fl., Rabehevitra 38 (MO, P); Mananara-Nord, forêt d'Antsanatribe à 3 km d'Antanambe, sur piste Ambodihazovola, 12.II.1990, fl. & fr., Raharimalala 269 (P [3 sheets]). Reg. unknown: sine loco, s.d., fl., Boivin s.n. (P); Jard. Bot. de Bourbon [cultivated], 15.IV.1847, fl., Boivin s.n.(P).

12. Homalium vohitsiandrianense Appleq., sp. nov. (Fig. 9).

Holotypus: Madagascar. Reg. Anosy [Prov. Toliara]: massif de Vohitsiandriana au N du Cap Andrahomana, 500 m, III.1955, fl., Service Forestier 11837 (P [P04679046]!).

Homalium vohitsiandrianense Appleq. differs from H. rakotovaoi Appleq. in its smaller, often proportionately broader leaves with acute (to rounded or emarginate) apices, shorter racemes, minute but often dense pubescence on pedicels and calyx cups, and very large sepal glands.

Tree to 10 m tall; twigs pale to medium brown, glabrous. Leaves ovate to broadly ovate (aberrantly broadly elliptical), (4–)5–7.8 × (2–)2.6–4.8 cm, relatively thin-textured; margin irregularly and shallowly crenulate to crenate-denticulate; base convex to rounded; apex acute (rounded, emarginate); both surfaces glabrous, drying pale greenish brown abaxially, mottled dark brown (green adaxially, glossy); secondary veins slightly prominent; petiole 10–16 mm, glabrous. Inflorescences racemose, (1.7–)3–4 cm; peduncle 0.3–1.3 cm; rachis glabrous; flowers (1–)3–5 per node; pedicels 3–6 mm, minutely but often densely pubescent. Flowers 4-merous; sepals broadly oblong, 1.5–1.7 mm on type, glabrous or glabrate, margins sparsely short-ciliate; sepal glands broadly elliptical and flattened, 1.2–1.3 × 0.8–0.9 mm; calyx cup minutely but rather densely pubescent; petals obovate, 3.4–4.2 mm on type, accrescence unknown, glabrous, margins not ciliate; filaments 1.8–2.4 mm; anthers broadly elliptical, 0.3 mm high.

Distribution, ecology and conservation status. – Homalium vohitsiandrianense is known only from a single 1955 collection on the southeastern massif of Vohitsiandriana (Fig. 2). The potential habitat will have been substantially reduced in the following 64 years by anthropogenic damage. If the population still exists, the appropriate assessment of its conservation status is “Critically Endangered” [CR B1ab(iii)+B2ab(iii)].

Notes. – Though H. vohitsiandrianense is known only from the type, it is quite distinct from other species occurring in the region. It is notable for its ovate leaves, racemes with flowers often in clusters of up to 5, long pedicels, broad sepals, and very large sepal glands. The plant is mostly glabrous except for minute, almost long-papillate, but often dense pubescence on the pedicels and calyx cup. It is presumed to be the sister species of H. rakotovaoi, a northern species that shares usually ovate leaves and 4-merous, long-pedicelled flowers often borne in clusters of several. That species has larger, proportionately narrower leaves, longer racemes, and much smaller sepal glands.