The Disposition of Trichopteris (Cyatheaceae)
1987; American Fern Society; Volume: 77; Issue: 3 Linguagem: Inglês
10.2307/1547497
ISSN1938-422X
Autores Tópico(s)Botany and Plant Ecology Studies
ResumoThe delimitation of genera and families has been a persistent problem in fern taxonomy, and the Cyatheaceae sensu stricto is no exception.Christensen (1905-06) adopted clearly artificial genera (Cyathea, Hemitelia, and Alsophila) based on complete (totally surrounding the sorus), partial, and absent indusia.He included Lophosoria and Metaxya in Alsophila.The latter two satellite genera are only distantly related to the major genera of the family, and nowadays are often placed in one or two families of their own.Holttum (1963) proposed a single genus Cyathea for the Flora Malesiana region with two very distinct subgenera, Sphaeropteris and Cyathea.Holttum has maintained (1981, p. 466) that the ''only subdivision of the genus clearly definable is that between subgenus Sphaeropteris and the rest."'This indicates that Alsophila and Cnemidaria are less distinct from Cyathea than all three are from Sphaeropteris, which is confirmed by the lack of hybrids with Sphaeropteris.In studying the species of the Flora Malesiana region, Holttum came to the fundamental conclusion, among many, that indusium type is not an important generic character, for within a few species it varies widely.Tryon (1970) divided the Cyatheaceae sensu stricto on the basis of scale characters, indusium presence or absence, and venation.He adopted the genera
Referência(s)