Seven New Species of Selaginella from Tropical South America

Abstract

For over a quarter of a century the genus Selaginella was studied by A. H. G. Alston (1902-1958), who produced a global survey of the genus by means of a series of regional taxonomic revisions. In most cases, these revisions are the most usable or even the only treatments available. Crabbe (1960, 1969) lists and indexes Alston's publications. For the Americas, Alston's first treatment was for Brazil (1936), followed by Argentina, Uruguay, and Paraguay (1939), the West Indies (1952), and continental North America south to Panama (1955). At the time of his death, Alston had amassed data on some 120 species found in tropical South America excluding Brazil. The manuscript he left was incomplete and contained a number of new species. Repeated attempts to complete the work have been delayed as new problems presented themselves and the scope of the project escalated. We have chosen to publish on this occasion seven species from the 26 that Alston recognized in his manuscript. The types of six of these species are at the Smithsonian Institution; the seventh is Selaginella mortoniana.