New synonyms and a new name in Asteraceae: Senecioneae from the southern African winter rainfall region

Abstract

A review of the genera Othonna and Senecio undertaken for the forthcoming Greater Cape plants 2: Namaqualand-southern Namib and western Karoo (Manning in prep.) led to a re-examination of the taxonomic status of several species. This was facilitated by the recent availability of high-resolution digital images on the Aluka website (www.aluka.org) of the Drege isotypes in the Paris Herbarium that formed the basis of many species described by De Candolle in his Prodromus systematis naturalis regni vegetabilis. These images made it possible to identify several names whose application had remained uncertain until now. Each case is briefly discussed, with citation of additional relevant herbarium specimens. The following species are reduced to synonomy: O. incisa Harv. is included in O. rosea Harv.; O. spektakelensis Compton and O. zeyheri Sond. ex Harv. are included in O. retrorsa DC.; S. maydae Merxm. is included in S. albopunctatus Bolus, which is now considered to include forms with radiate and discoid capitula; S. cakilefolius DC. is included in  O. arenarius Thunb.; S. pearsonii Hutch, is included in O. aspertdus DC.; S. parvifolius DC. is included in S. carroensis DC.; S. eriobasis DC. is included in S. erosus L.f.; and S. lobelioides DC. is included in S. flavus (Decne.) Sch.Bip. The name S. panduratus (Thunb.) Less, is identified as a synonym of S. erosus L.f. and plants that are currently know n under this name should be called S. robertiifolius DC. The confusion in the application o f the names O. perfoliata (L.f.) Jacq. and O. filicaulis Jacq. is examined. O. perfoliata is lecto- typified against a specimen in the Linnaean Herbarium (LINN)  w ith radiate capitula. The name O. filicaulis correctly applies to a radiate species and is treated as a synonym of O. perfoliata. The vegetatively similar taxon with disciform capitula that is currently known as O. filicaulis should be known as ()  undulosa (DC.) J.C.Manning  Goldblatt, comb. nov. The new name O. daucifolia J.C.Manning Goldblatt is provided to replace the later homonym O. abrotanifolia (Harv.) Druce.