Two hundred years after their gathering, the pioneering lichen collections made by Archibald Menzies between 1784 and 1802 during his career as a naval surgeon are recorded and discussed. The bulk of Menzies's lichens come from three major collection periods: the Halifax Station (Nova Scotia) of 1784–1786; his time as surgeon to James Colnett on the circumnavigation of the Prince of Wales (1786–1789); and his extensive tour as naturalist to Vancouver's Discovery expedition (1791–1795). Menzies's extra-European lichen collections were the most extensive ever made during the 18th century and contain many first discoveries and type collections: (1) Nova Scotia, 16 taxa in 11 genera, 1 type; (2) Staten Island, 32 taxa in 19 genera, 5 types; (3) west coast of North America, 83 taxa in 45 genera, 11 types; (4) Sumatra, 10 taxa in 7 genera; (5) Cape of Good Hope, 30 taxa in 23 genera; (6) New Zealand, 14 taxa in 6 genera; (7) Tahiti, 5 taxa in 4 genera; (8) Hawaii, 25 taxa in 13 genera; (9) St Helena, 10 taxa in 8 genera. Major repositories of Menzies lichens are the Royal Botanic Garden Edinburgh, the Linnean Society of London (James Edward Smith herbarium) and the Natural History Museum, London.

The floristic nature of central Brazilian forests, as well as their links to other main forest formations of eastern tropical South America, is assessed by means of multivariate analyses of 106 existing floristic checklists and by the analysis of a series of dot-maps showing the distribution of 55 woody species. Most species of central Brazilian forests seem to conform to two main distribution patterns: (1) species of deciduous and semideciduous forests are dependent essentially on the occurrence of patches of soils of intermediate to high fertility within the cerrado domain and tend to be distributed mostly along a northeast-southwest arch connecting the caatingas to the chaco boundaries; (2) considerable numbers of gallery forest species are dependent on high soil moisture and many appear to link the Amazonian and Atlantic rainforests by crossing the cerrado region in a northwest-southeast route via the dendritic net of gallery forests. Many gallery forest species are habitat generalists, some even occurring in the cerrado vegetation. Nevertheless, significant numbers of gallery endemics are also present. Galleries of the west and north of the Cerrado Province show stronger floristic links to the Amazonian rainforests, while those of the centre and south show stronger affinity with the montane semideciduous forests of southeastern Brazil. Present-day distribution patterns are discussed in the light of the current knowledge of palaeoenvironmental changes in the Neotropics.

The generic position of Caralluma dodsoniana Lavranos (Asclepiadaceae) is investigated. It is concluded that a monotypic genus to accommodate it is unnecessary and that it should be incorporated into the genus Pseudolithos P. R. O. Bally as P. dodsonianus (Lavranos) Bruyns & Meve.

The discovery in historic herbaria of an overlooked extinct endemic from the island of St Helena is reported. The first descriptions of St Helena Ebony, Trochetiopsis melanoxylon (Sterculiaceae), and the specimens associated with them in the herbaria of Oxford University (OXF) and the Natural History Museum, London (BM), do not match living and later-collected material, and instead represent an extinct plant. A new name is therefore needed for living St Helena Ebony: Trochetiopsis ebenus Cronk sp. nov. The hybrid between this species and the related T. erythroxylon is also described here: Trochetiopsis × benjamini Cronk hybr. nov. (Sterculiaceae), and chromosome counts of 2n = 40 are reported for the hybrid and both parents for the first time. The re-assessment of the extinct ebony emphasizes the importance of historic herbarium collections for the study of species extinction.

Didymocarpus rodgeri (incl. var. siamensis) is reduced to a synonym of D. aureoglandulosus (SE India, Burma and Thailand); D. subalternans var. curvicapsa (Nepal–Sikkim) is raised to specific rank, and a new species, D. triplotrichus (Darjeeling distr. and Sikkim), is described. Lysionotus himalayensis is redetermined and reduced to synonymy under L. serratus; as a result L. atropurpureus, which name it had recently superseded, is reinstated. Aeschynanthus kingii and A. levipes are both transferred to Lysionotus, while L. wardii and L. gracilipes are reduced to synonymy under L. pubescens. Notes and new records are provided for L. confertus and L. serratus var. pterocaulis.

A new species of Potentilla sect. Leptostylae (Rosaceae), P. montisvictoriae, endemic to Mt Victoria, C Burma, is described. Potentilla montisvictoriae differs from P. leuconota D. Don in having free auricles on the stipules of the radical leaves, patent or descending hairs on the rachis and peduncles, obovate petals, styles longer than ovaries and entire or shallowly incised auricles on the stipules of the cauline leaves.

Two new genera, Stygiomyces (Coelomycetes) with type species S. galliformis on Pseudocyphellaria faveolata from Tasmania, and Pseudonitschkia (Dothideales) with type species P. parmotrematis on Parmotrema tinctorum and P. pseudotinctorum from South America (Paraguay, Venezuela), Africa (Ivory Coast, Malawi, South Africa) and Nepal, are described. Their placement and differences from similar genera are discussed.