Open AccessMorphology and anatomy of roots in the filmy fern tribe Trichomaneae H. Schneider (Hymenophyllaceae, Filicatae) and the evolution of rootless taxa
Author(s) -
SCHNEIDER HARALD
Publication year - 2000
Publication title -
botanical journal of the linnean society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.872
H-Index - 68
eISSN - 1095-8339
pISSN - 0024-4074
DOI - 10.1111/j.1095-8339.2000.tb01853.x
Subject(s) - biology , botany , epiphyte , fern , tribe , taxon , monophyly , stele , rhizome , morphology (biology) , phylogenetics , zoology , clade , biochemistry , sociology , anthropology , gene
The filmy ferns of the tribe Trichomaneae, synonymous with Tichomanes s.L., show various constructions of their root system that correspond to different growth forms as well as ecology. Most terrestrial species possess a short erect shoot with numerous thick roots, whereas epiphytic species have a long creeping rhizome that may develop a few thin roots. An evolutionary progression from ferns with well‐developed roots to ferns without roots is postulated. Rootless species occur in two monophyletic groups, subgen. Crepidomanes and subgen. Didymoglossum. The results are summarized in a new classification for the tribe. Secondary simplification, e.g. loss of roots, is discussed as an adaptive trait in epiphytic plants. Transformed structures such as root‐like shoots and adhesive hairs are observed in rootless taxa and their evolutionary significance is briefly discussed. Climbing filmy ferns are recognized as possible closely related species based on the similarities in their root systems.