Contribution
Spore surface structure of Sphagnum
Cao, Tong; Vitt, Dale H.
Nova Hedwigia Band 43 Heft 1-2 (1986), p. 191 - 220
21 références bibliographiques
publié: Aug 20, 1986
DOI: 10.1127/nova.hedwigia/43/1986/191
ArtNo. ESP050004301011, Prix: 29.00 €
Abstract
The critical point dried spores from 87 populations of 33 species of Sphagnum (65% of species in North America) are illustrated with Scanning Electron Micrographs. Sphagnum spores are heteropolar, tetrahedral and are 20-50 μm in diameter. On the proximal surface, trilete laesurae are surrounded by a well-developed margo. Five major characters have significant variation: 1) size in diameter, 2) thickness of exine, 3) aperture structure of proximal face, 4) wall structure of distal surface, and 5) sculpture of the perine. There is considerable intra-specific and infra-generic variation in most characters. However, some species appear to have distinctive spore features. Likewise the sections of the genus, although not totally distinct, have particular trends that are noteworthy. Section Cuspidata has many species with larger spores; sections Sphagnum and Squarrosa have most species with thin exines; many species of section Sphagnum have a large ratio of length of laesura to radius of the spore, likewise these mostly have a bifurcate distal surface marking. Section Acutifolia has species often having well-developed perine.
Mots-clefs
Sphagnum • Scanning Electron Micrographs • spores • trilete laesurae • genus • perine