Till 1992 (Article) Tillandsia

Systematics and evolution of the tropical and subtropical Tillandsia subgenus Diaphoranthema (Bromeliaceae)

Author(s):—W. Till

Publication:—Selbyana 13: 88-94. (1992)

Abstract:—All currently known taxa of Tillandsia subgenus Diaphoranthema have been studied and treated in a taxonomie revision and other papers. Six groups of species ("aggregates"), distinguished by floral morphology and certain vegetative features, are recognized. These groups contain a series of taxa that display morphological reduction accompanied by shortening of life cycles (neoteny). Polyploidy is frequent within Diaphoranthema. Compared with subgenus Phytarrhiza, the closest related subunit of the genus Tillandsia, neotenic species of Diaphoranthema have migrated into more isolated and climatically extreme areas than have any other Tillandsia species. Abbreviated life cycles and strong tendencies of autogamy and cleistogamy, in connection with increasing polyploidy, are proposed to be responsible for the high stress tolerance and dispersibility of the species of Diaphoranthema.

Taxonomy:—Tillandsia porongoensis Moved to Tillandsia subgen. Diaphoranthema .