科研之友
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摘要
The southern African genus Bolandia Cron. was described for two species of perennial herbs with radiate, yellow capitula and diagnostic dimorphic cypselae. The ray and outer disc cypselae are falcate-fusiform and triangular in section, with a convex, sparsely puberulous outer surface and a keeled, glabrous inner surface, and the inner florets are fusiform and puberulous throughout. A small group of perennial herbs with discoid capitulae until now treated as Senecio scapiflorus (L'Her.) C.A.Sm. sensu lato is shown to have the same dimorphic cypselae as Bolandia, and phylogenetic analysis of plastid and nuclear sequence data places these taxa in a clade with that genus and apart from other species of Senecio. Herbarium and field studies support the division of the S. scapiflorus complex into three groups of populations differing in leaf morphology, flower colour, geographical distribution and ecology. These are recognized at the rank of species and transferred to the genus Bolandia as B. pinnatifida (Thunb.) J.C.Manning & Cron, B. glabrifolia (DC.) J.C.Manning & Cron and B. elongata (L.f.) J.C.Manning & Cron respectively. The circumscription of Bolandia, which now includes five species, is emended to include discoid taxa with yellow, white or mauve florets. A complete taxonomic and nomenclatural revision, including numerous new synonyms, full descriptions and distribution maps, is provided for the discoid species. Finally, the later inclusion by Candolle (1838) of only Brachyrhynchos junceus Less. in the type section of the genus is interpreted as effective lectotypification of the genus, precluding the possibility that it is an earlier name for Bolandia.
- 出版日期2011-1
