Taxonomic Significance of Leaf Indumentum Characteristics of the Genus Biscutella(Cruciferae)

No Thumbnail Available
Date
1992
Authors
Olowokudejo, J. D.
Journal Title
Journal ISSN
Volume Title
Publisher
Springer
Abstract
Leaf indumentum characteristics of 52 taxa of the genus Biscutella are examined by hand lens, stereo- and scanning electron microscopy. Hairs occur on all vegetative organs of all taxa except B. laevigata subsp. lucida which is completely glabrous and shining. Trichomes are simple unicellular and attenuate but are variable in structure, size and distribution both within and between species. Eight types of indumenta are recognized and these include hispid/hirsute, puberulent, tomentose, villous and velutinous. Each type varies in abundance from sparse to dense within the genus. In a few cases, indumentum is species-specific; for example, the whitish tomentose hair covering of B. frutescens distinguishes this species from the remaining species of the genus. In other taxonomically important species affinities are indicated. The occurrence of indumentum is discussed in relation to the various roles usually ascribed to this feature.
Description
Keywords
Biscutella , Cruciferae , Trichome , Indumentum , Taxonomy , Europe , SEM
Citation
Olowokudejo, J. D. (1992). Taxonomic Significance of Leaf Indumentum Characteristics of the Genus Biscutella(Cruciferae). Folia Geobotanica & Phytotaxonomica 27(4): 401-417