Jongkind, C.C.H. (2016). Maesobotrya liberica Jongkind (Phyllanthaceae), a new forest species from Liberia. Candollea 71 : 275–279. In English, English abstract. DOI: http://dx.doi.org/10.15553/c2016v712a12
A new species of Maesobotrya Benth. (Phyllanthaceae) from the evergreen forest of Liberia is described. It is the second Maesobotrya Benth. species in western Africa (Upper Guinea). It resembles Maesobotrya pauciflora Pax and Maesobotrya oligantha O. Lachenaud & Breteler from west-central Africa (Lower Guinea) by its male and its female inflorescences that are both small and axillary. Illustrations are provided along with a distribution map. A preliminary assessment of its risk of extinction following the IUCN Red List Categories and Criteria results in a status of “Endangered”.
Introduction
Maesobotrya Benth. is an African genus in the Phyllanthaceae (formerly Euphorbiaceae) with about 20 species. The genus can be recognized by the bipulvinate petiole of clearly variable lenght, the leaf blade margin with tiny teeth each bearing a tuft of straight hairs and the 5-merous male or female flowers without petals in separate inflorescences. Most of the species are restricted to the Guineo-Congolian forests (Léonard, 1994 ; Breteler, 2012). Up till now the only Maesobotrya species recognised from the Upper Guinean subcentre of endemism (sensu White, 1979) was M. barteri (Baill.) Hutch. This species is known for the edible, red fruits growing on its stem (Keay, 1958), it is often called “bushcherry”. Characteristic woody bumps show the places where the fruits grow time after time (Fig. 1).
Recently we have found in south-east Liberia Maesobotrya shrubs up to 4 m high with all the flowers and fruits in small inflorescences (< 2 cm long) near the end of the branches between the leaves. The stems of these shrubs were without any trace of present or past cauliflory. The only two Maesobotrya species that share these characters, M. pauciflora Pax and M. oligantha O. Lachenaud & Breteler, are found in west-central Africa (Lower Guinean subcentre of endemism). Between the population in Liberia and the two central African species there is a gap of more than 1,900 km (Fig. 2). The Liberian plants resemble M. oligantha and M. pauciflora but differ enough from both to describe them as a new species, M. liberica Jongkind. Maesobotrya liberica, M. oligantha and M. pauciflora differ in indumentum and leafshape and grow at different altitude (Table 1).
The area in south-east Liberia where the new species is found is known to be home to several local endemic species, like Gilbertiodendron obliquum (Stapf ) J. Léonard (de la Estrella & Devesa, 2014), Heckeldora jongkindii J.J. de Wilde (de Wilde, 2007), Jollydora armandui Jongkind ( Jongkind, 2012) and several others. At the moment an important part of the forest in this area is making place for oil palm plantations.
Systematics
Maesobotrya liberica Jongkind, spec. nova (Fig. 3–4).
Typus: Liberia : c. 50 km east of Greenville, 5°04′14″N 8°30′05″W, 60 m, 10.III.2014, fr., Jongkind et al. 12333A (holo-: BR!; iso-: G!, WAG!).
Maesobotrya liberica Jongkind resembles M. pauciflora Pax and M. oligantha O. Lachenaud & Breteler with similar short, axillary, inflorescences, but differs by its indumentum and leaf shape.
Shrub up to 4 m high with branches up to 4 cm in diam. Bark strongly fissured. Stipules paired, lanceolate, up to 8 × 1.5 mm, with appressed hairs along the edge and sometimes on the outside along a line in between the edges, often persistent at younger nodes. Leaves alternate; petiole bipulvinate, 0.3–4.5 cm long, with short, more or less appressed, pale hairs; blade obovate to elliptic, 5.5–23.5 × 2.2–10 cm, acute at base, acuminate at apex, slightly bullate, the margin with small teeth each bearing a tuft of straight hairs, blade in bud completely covered with pale hairs, in the adult stage almost glabrous except for the midrib and the main lateral nerves below; 5–7 pairs of main lateral nerves. Male and female inflorescences axillary, usually solitary, racemose, rachis < 2 cm long, more or less appressed and pale hairy, bracts and bracteoles 1 mm or smaller, male with 7–18 flowers, female with 10–16 flowers. Flowers green, yellowish or reddish, with a joint in the pedicel close to the inflorescence rachis, sepals imbricate and glabrous, petals absent. Male flowers usually single along the rachis; pedicel 1.5–3 mm long, glabrous; sepals ca 1 mm long, elliptic, glabrous; 5 glabrous stamens, opposite the sepals; filaments free, 1.5–2 mm long; anthers c. 0.2 mm long, erect, dorsifixed, introrse, thecae parallel, longitudinally dehiscent ; disk with lobed edge, short hairy, with in the centre a rudimental ovary. Female flowers single along the rachis; pedicel 0.5–2 mm long, glabrous or with a few hairs ; sepals c. 1 mm in diameter, elliptic, glabrous ; disk lobed, hairy; ovary with scattered, appressed hairs, already early visible between sepals; styles very short ; stigmas (2?-)3, bifid, recurved. Fruit ovoid, acute at apex, c. 12 mm high, fleshy, with a few hairs or glabrous, red, one seeded.
Distribution and ecology — Only known from the undergrowth of evergreen lowland forest in Sino County in southeast Liberia.
Conservation status — Maesobotrya liberica is only known from five locations. The species is not known from protected areas and forest close to the places where it was collected is changed at the moment into oil palm plantations. With an extent of occurrence (EOO) of 318 km2 and an area of occupancy (AOO) is 20 km2 (based on a cell width of 2 km), M. liberica is assigned a preliminary conservation status of “Endangered” [EN B1ab(i, ii, iii)+2ab(i, ii, iii)] following IUCN Red List Categories and Criteria (IUCN, 2012).
Notes. — The genus Maesobotrya is said to be dioecious but Jongkind et al. 12333A, 12333B from M. liberica show, on separate branchlets, male or female inflorescences. It is not clear if these branches are from the same shrub or from different shrubs growing close together.
On the top of part of the fruits only 2 styles are counted, maybe in these cases one style dropped after flowering but it is also possible that female flowers have sometimes only 2 styles.
The fruits of the cauliflorous species in this genus are known to be dehiscent at maturity. In our new species, and maybe also in M. oligantha, the fruits seem to stay closed.
Paratypi. — Liberia : African Fruit Company plantation, 28.VII.1977, st. fl., de Gier & Goll 48 (MO, WAG); 20 miles N of Sinoe, 16.I.1969, st. fl., JWA Jansen 1102 (BR, K, MO, P, WAG); c. 50 km E of Greenville, 5°04′14″N 8°30′05″W, 60 m, 10.III.2014, pist. fl., Jongkind et al. 12333B (BR, G, WAG); c. 50 km E of Greenville, 5°04′40″N 8°34′27″W, 163 m, 11.III.2014, pist. fl., fr., Jongkind et al. 12385 (BR, G, P, WAG); E of Wiado village, 5°07′58″N 8°54′27″W, 55 m, 3.II.2016, st. fl., Jongkind & Sambolah 12943 (BR, WAG).
Fig. 1.
Maesobotrya barteri (Baill.) Hutch. from Guinea : stem with immature green fruits showing the woody bumps were the fruits grow from every fruiting season. [Photo : C. Jongkind]
Fig. 2.
Distribution map with to the right Maesobotrya pauciflora Pax (surrounded by a black line) overlapping M. oligantha O. Lachenaud & Breteler (squares), and to the left M. liberica Jongkind (circles).
Fig. 3.
Maesobotrya liberica Jongkind. A. Leaf from below and male infloresences; B. Stem c. 4 cm in diam. [Jongkind et al. 12943] [Photo : C. Jongkind]
Table 1.
Differences between Maesobotrya barteri (Baill.) Hutch., M. liberica Jongkind, M. pauciflora Pax and M. oligantha O. Lachenaud & Breteler.
Fig. 4.
Maesobotrya liberica Jongkind. A. Habit with male inflorescence ; B. Leaf margin from below ; C. Male inflorescence ; D. Male flower ; E. Same as D but with sepal removed, showing the hairy lobes of the disk ; F. Female flower ; G. Female inflorescence and stipules ; H. Same as G but with sepal removed, showing hairy disk ; I. Fruit. [A–E : Jongkind 12333B, BR ; F–H : de Gier & Goll 48, WAG ; I : Jongkind 12333A, BR] [Drawing : H. de Vries]
Acknowledgements
The author would like to thank the reviewers for their comments that help improve the manuscript, especially Olivier Lachenaud. He also would like the staff of the Liberian office of Fauna & Flora International for their support for the field work and Hans de Vries for the fine line drawing. The most recent expedition on which he could study M. liberica was funded by the “Hugo de Vries Fonds”.
