Nucleotide sequence data from three chloroplast genes (rbcL, rps4 and psbA), one nuclear gene (the ribosomal LSU) and one mitochondrial gene (nad5) were assembled for 173 species in 117 genera of liverworts, making this the largest molecular phylogeny of the group to date. Analyses of these data provide support for the monophyly of the liverworts, and for previously resolved backbone relationships within the Marchantiophyta. The earliest divergence involves the “simple thalloid” taxa of the Haplomitriaceae and Treubiaceae. A Blasiaceae/complex thalloid clade is resolved as sister to all remaining liverworts. The leafy liverworts do not resolve as monophyletic. The separation of the Aneuraceae/Metzgeriaceae from all other simple thalloids and their placement within the “leafy” clade as sister to the enigmatic leafy genus Pleurozia, as suggested in earlier molecular phylogenies, is also supported by this far larger data set.

In its native Europe, the lichen Lecanora conizaeoides is an obligate acidophile: it always grows on substrates with a low pH. Its notorious, rapid spread through Europe in the 20^th century followed an increase in atmospheric sulfur dioxide pollution that artificially acidified many substrates on which this lichen would normally never occur. During the last 50 years, this species has appeared in several scattered, coastal North American sites. In 2000, a new population was discovered in an Atlantic white cedar swamp in eastern Massachusetts; subsequently, three additional rural populations, as well as three suburban populations, have been found in the area. Specimens from these seven populations are morphologically and chemically indistinguishable from other North American and European specimens. Substrate pH measurements reveal that, with one exception, all substrates colonized by L. conizaeoides in eastern Massachusetts are highly acidic (pH < 4), thus demonstrating that this lichen is behaving as an acidophile, just as it does in Europe. At the four rural sites, L. conizaeoides displays an almost singular affinity for Atlantic white cedar (Chamaecyparis thyoides), growing on its wood and, less frequently, its bark. But at the three suburban sites, this lichen colonizes the bark of various tree species, most of which give pH values noticeably lower than at the rural sites. The acidification of these tree species at the suburban sites cannot be explained by high concentrations of atmospheric sulfur dioxide, however, because these concentrations have never approached the levels recorded in Europe during the spread of this lichen there. All our observations suggest that, in eastern Massachusetts, L. conizaeoides established itself first in rural Atlantic white cedar swamps, and is subsequently spreading to other, suburban sites which contain sufficiently acidic substrates. This pattern of invasion is strikingly similar to that hypothesized for Europe by Wirth (1985), who suggested that L. conizaeoides originated in Pinus mugo bogs, from which it gradually expanded into more urbanized areas.

Water and pH are documented correlates of lichen and moss presence and dominance on rock surfaces, yet standard, defensible methods for their measurement are lacking. To address this deficiency we devised and tested methods for measuring absorption of liquid and atmospheric water, water retention and pH of rock surfaces. To adjust these measurements to cryptogam-relevant units we also developed an inexpensive method for determining rock surface area—by finding the increase in rock mass after applying a monolayer of homogenous sand grains with a known mass per unit surface area. We applied these techniques to compare volcanic (andesitic) and limestone rock surfaces from Yellowstone National Park, U.S.A. Andesitic rocks were less basic, absorbed more liquid and atmospheric water, and retained more water over time than limestone rocks.

The lichen flora of Vietnam was investigated. A bibliography is presented of all papers citing lichen species from what is now Vietnam, and a comprehensive checklist is given, with the reported and the current names. To give an impression of the state of the current knowledge of the lichen flora, the results of a recent field trip are presented as well. The total lichen flora known to date comprises 275 species, 122 of which are reported here from Vietnam for the first time.

Twenty-six lichen taxa are reported for the first time from either the Tierra del Fuego Archipelago, the Falkland Islands (Islas Malvinas), or both, from collections made by Henry Imshaug and his co-workers between 1968 and 1971 and now housed in the herbarium of Michigan State University (msc). Of these, Alectoria sarmentosa subsp. vexillifera, Bartlettiella fragilis, Micarea incrassata, M. melaena, Parmelia kerguelensis, Rhizocarpon infernulum and R. submodestum are reported for the first time from South America, and Alectoria nigricans, Brigantiaea fuscolutea, Buellia anisomera, B. subcervina, Caloplaca isidioclada, C. millegrana, Lecidella wulfenii and Megalospora tuberculosa are reported for the first time from Argentina or the Falkland Islands.

Pylaisiopsis (Broth.) Broth. is revised based on the molecular phylogenetic analysis and detailed morphological investigation. The genus is considered to be synonymous with Pylaisia (Hypnaceae). An older combination, Pylaisia speciosa (Mitt.) Wilson ex A. Jaeger, is selected for Pylaisiopsis speciosa (Mitt.) Broth. A description and illustrations of the species are provided. The taxonomic position of Foreauella orthothecia (Schwägr.) Dixon & P. de la Varde is also discussed.

Barbula santessonii E. B. Bartram and B. fusca Müll. Hal., two neglected South American species are transferred to the genus Didymodon Hedw. Both species are described and distinguished from closely related species with which they may be confused. Each species is illustrated for the first time and its distribution mapped. Barbula fuscoviridis Broth. ex Thér. is synonymized with Didymodon fuscus.

Encalypta texana is a new, gymnostomous species from west Texas, U.S.A. It differs from other small, gymnostomous, southwestern United States species of Encalypta in having oblong to elliptical, broadly acute, ventrally papillose leaves with subpercurrent costae and basally recurved margins, irregularly fringed calyptrae, non-furrowed capsules and finely pitted spores.

The rare moss, Tortella limbata, previously known only from the type locality on Grand Canary Island (Canary Islands, Spain), and misjudged as a synonym of Trichostomum brachydontium, is here reinstated, reported from La Gomera (Canary Islands) and the Madeira Archipelago (Portugal), lectotypified, described and illustrated.

The moss Tortella alpicola Dixon (Pottiaceae) is reported as new to western Europe (west of the Urals), where it was found in the south of Spain (Sierra Nevada range). Its distribution, diagnostic characters and differentiation from some closely related European taxa, with which it may be confused, are discussed. A map of its known distribution and light microscope micrographs are provided.

J. Eggers collected a Diplasiolejeunea in Costa Rica with peculiar lobe dentition, described here, as Diplasiolejeunea eggersii, new to science. The main differences from the related Diplasiolejeunea pluridentata and D. papilionacea are given. Because the latter species, from Venezuela, had only a very short protologue, an additional description is given here, based mainly on specimens collected from near the type locality.

The new species, Schismatomma physconiicola, lichenicolous on the thallus of Physconia cf. muscigena, is described from Mexico. It is the first known non-lichenized, lichenicolous species in the genus Schismatomma.

Allen, Bruce. 2005. Maine mosses: Sphagnaceae–Timmiaceae. Memoirs of The New York Botanical Garden 93: [i–xii] 1–420. The New York Botanical Garden Press, 200^th Street and Kazimiroff Boulevard, Bronx, New York 10458-5126, U.S.A. [ISBN 0-89327-471-2]. Price: US $75 (hard cover); Order No. MEM 93; shipping and handling add 5% $6.00 of subtotal, outside USA 6% $7.00 of subtotal. (718) 817-8721, fax (718) 817-8842; e-mail nybgpress@nybg.org;  http://www.nybg.org/.

Frahm, Jan-Peter & Wolfgang Frey. 2004. Moosflora, 4. Neubearbietete und erweiterte Auflage. 538 pp., mit 108 Abbildungen. Ulmer UTB, Eugen Ulmer GmbH & Co., Stuttgart, Germany. [ISBN 3-8001-2772-5 (Ulmer); ISBN 3-8252-1250-5 (UTB)] Price €24.90 shipping and postage (softcover). Available from:  http://www.ulmer.de/.

Fałtynowicz, Wiesław. 2003. The lichens, lichenicolous and allied fungi of Poland—an annotated checklist. Biodiversity of Poland 6: 1–435. 2003. [ISBN 83-89648-06-7] Price: 58 PLN (19 €). Available from: W. Szafer Institute of Botany; email: ed-office@ib-pan.krakow.pl

Dalby, Kery & Claire Dalby. 2005. Shetland Lichens. Shetland Amenity Trust, Shetland. 120 pp., with color illustrations. [ISBN 0-9543246-3-3] Price £12 postage and handling. Available from: Shetland Biological Records Centre, Shetland Amenity Trust, Garthspool, Lerwick, Shetland ZE1 0NY, U.K. email: sbrc@zetnet.co.uk