Open Access

Nuclear ribosomal DNA internal transcribed spacer (ITS) 1/2 sequences of the Colombian endemic Gradsteinia andicola were determined and compared with those of 16 other species of the Hypnales (Amblystegiaceae, Brachytheciaceae, Hypnaceae, Plagiotheciaceae and Rhytidiaceae). In a maximum parsimony tree Gradsteinia andicola belongs to a well supported clade consisting of Amblystegium, Cratoneuron, Cratoneuropsis, Hypnobartlettia and Palustriella, and seems to be closely related to Cratoneuropsis relaxa from New Zealand. Gradsteinia andicola is therefore transferred to Amblystegiaceae, but the genus Gradsteinia is maintained. The systematic relationship of Amblystegiaceae and Donrichardsiaceae is discussed.

The 1996 Chagos Expedition provided the first opportunity to study the archipelago’s lichen flora. Seventeen of the 55 islands were ecologically investigated, some in more detail than others, and lists and representative collections of lichens have been assembled for many of them. In all, 67 taxa have been recorded, 52 to specific level. Although the islands have a low biodiversity for cryptogamic plants, as would be expected in terms of their relatively young age, remoteness and small terrestrial surface areas, those taxa that are present are often found in abundance and play significant ecological roles. There is a good correlation between total lichen biodiversity and island size, despite the fact that Cocos nucifera is such an important substratum for cryptogamic plants and its presence on all islands studied provides a consistently high associated species count. Comparisons of lichen floras for ten island and coastal tropical areas show good correlations (based on the Sörensen Coefficient) within the Indian Ocean as would be expected, but poorer correlations exist within and between Pacific Ocean and neotropical floras. Ranked correlations between Chagos and other floras are in the sequence Maldives > Laing Island > Aldabra > Tuamotu > Pitcairn > N.Mariana & Belize > Guadeloupe > Cook. When coefficients are calculated using only the Physciaceae, different correlations and sequences are derived, but the affinities of the Indian Ocean islands remain strong. However, although the lichen flora of Chagos is characteristic for an Indian Ocean, it is dominated by pantropical species.

The known geographical distribution of 12 bryophyte species is extended by confirmation of their presence in the state of Pernambuco. Leptoscyphus porphyrius (Nees) Grolle, Harpalejeunea uncinata Steph., Chryso-hypnum diminutivum (Hampe) Buck and Porotrichum korthalsianum (Dozy & Molk.) Mitt. are new to northeastern Brazil. The material studied was collected in remnants of Atlantic Forest situated at altitudes of 100-1.100m. The principal taxonomic characteristics are cited, with ecological and distributional commentary provided.

Dicranella hilariana (Mont.) Mitt., a pan-neotropical moss species, is reported for the first time from the Antarctic botanical zone. It was found on geothermally heated ground near fumaroles on Visokoi, Candlemas and Bellingshausen Islands in the volcanic archipelago of the South Sandwich Islands. Dicranella recurvata Ochyra, Arts & Lewis-Smith, nom. nud., is reduced to synonymy with D. hilariana. The Antarctic plants of D. hilariana are briefly described and illustrated, including the rhizoidal tubers which have not previously been reported in this species. The global distribution of D. hilariana is briefly reviewed and mapped. It is suggested that the species reached the Antarctic via long-distance dispersal from South America by the prevailing strong westerly winds.

Twelve genera are excluded from the sub-Saharan Africa checklist based on evidence from literature or re-identification. Atractylocarpus, Chorisodontium, Ctenidium, Dicranodontium, Homalia, Isothecium, Lasiodontium, Meesia and Potamium are excluded as the collections belong to other genera, and Camptochaete, Phyllodrepanium and Ptychomnion are excluded because of evidence of mistaken (or no longer existing) localities. As a consequence, the following families no longer are known from Africa: Echinodiaceae, Lembophyllaceae, Phyllodrepaniaceae and Ptychomniaceae. Ectropothecium nishimurii O’Shea & Ochyra, nom. nov. replaces Ectropothecium mauritianum (Broth.) Nishimura, hom. illeg., and Kindbergia kenyae (Dixon ex Tosco & Piovano) O’Shea & Ochyra, comb. nov. replaces Isothecium kenyae Dixon ex Tosco & Piovano. Lasiodontium mieheanum Ochyra in S. Miehe & G. Miehe, nom. nud., is a synonym of Daltonia angustifolia Dozy & Molk. and accordingly Lasiodontium Ochyra in S. Miehe & G. Miehe, nom. nud., must be placed in synonymy with Daltonia Hook. & Taylor.