A partial revision of the genus Aristea (Iridaceae) in South Africa, Swaziland, Lesotho, Transkei and Ciskei

Abstract

A large amount of herbarium material of Aristea, collected in the study area, was re-examined. All of Weimarck’s species concepts (Weimarck 1940) concerning this assemblage of Aristea are upheld with the exception of A. torulosa Klatt which has been excluded. The species concepts that have been upheld, and which have been further defined in this study, are the following: Aristea anceps Ecklon ex Klatt, A. cognata N.E. Brown ex Weimarck, A. flexicaulis Baker, A. galpinii N.E. Brown ex Weimarck, A. montana Baker, A. woodii N.E. Brown, A. angolensis Baker (four subspp.), A. schizolaena Harvey ex Baker, A. grandis Weimarck, A. gerrardii Weimarck, A. compressa Buchinger ex Baker, A. ecklonii Baker, A. pusilla (Thunb.) Ker. (two subspp.) and A. platycaulis Baker. The most useful characters for the taxonomic delimitation of these species are: the appearance of the bracts, capsules, basal leaves, cauline leaves and the shape of the style branches. The latter character is new to the taxonomy of this genus. The possible phenetic relationships between these species and the current tribal position of the genus are discussed and illustrated. Most of the species are distributed along the Drakensberg Mountain Range but a few species are restricted to a more coastal or near coastal habitat. New lectotypes have been selected for A. anceps and A. ecklonii. S. Afr. J. Bot. 1985, 51: 209–252 ‘n Groot hoeveelheid herbariummateriaal van Aristea, versamel in die studie gebied, was herondersoek. Weimarck se spesies begrippe (Weimarck 1940), met betrekking tot hierdie versameling van Aristea, is almal behou, met die uitsondering van A. torulosa Klatt wat uitgesluit is. Die spesiesbegrippe wat behoue gebly het, en wat verder gedefinieer is in hierdie studie, is die volgende: Aristea anceps Ecklon ex Klatt, A. cognata N.E. Brown ex Weimarck, A. flexicaulis Baker, A. galpinii N.E. Brown ex Weimarck, A. montana Baker, A. woodii N.E. Brown, A. angolensis Baker (vier subspp.), A. schizolaena Harvey ex Baker, A. grandis Weimarck, A. gerrardii Weimarck, A. compressa Buchinger ex Baker, A. ecklonii Baker, A. pusilla (Thunb.) Ker. (twee subspp.) en A. platycaulis Baker. Die karakters met die mees nut vir die taksonomiese grensreëling van hierdie spesies is: die voorkoms van die skutblare, kapsules, onderste blare, stamblare en die vorm van die stempeltakke. Die laasgenoemde karakter is nuut ten opsigte van die taksonomie van hierdie genus. Die moontlike fenetiese verwantskappe tussen hierdie spesies en die huidige stam posisie van die genus is bespreek en geillustreer. Meeste van die spesies is oor die Drakensbergreeks versprei, maar ‘n paar spesies is beperk tot ‘n meer kusof naby kushabitat. Nuwe lectotipe is uitgesoek vir A. anceps en A. ecklonii . S.-Afr. Tydskr. Plantk. 1985, 51: 209–252