Typification of Names in Nine Species of Arctotis (Asteraceae, Arctotideae) from the Succulent Karoo, South Africa Robert J. McKenzie* and Nigel P. Barker Molecular Ecology and Systematics Group, Department of Botany, Rhodes University, P.O. Box 94, Grahamstown, 6140, South Africa. *Author for correspondence: r.mckenzie@ru.ac.za ABSTRACT . In preparation for the treatment of Arctotis L. (Asteraceae) in the upcoming Conspectus of the Trans-Cape Succulent Karoo Flora of South Africa, the typification of names and synonymy for nine Arctotis species that occur within the Succulent Karoo region, South Africa, are clarified. The author citation for A. argentea is corrected from Thunb. to A. argentea Aiton, and the lectotype is selected. In addition, lectotypes are designated for A. auriculata Jacq., A. campanulata DC., A. campanulata var. puberula DC., A. canescens DC., A. cineraria Jacq., A. cuprea Jacq., A. denudata Thunb., A. diffusa Thunb., A. fastuosa Jacq., A. flaccida Jacq., A. flammea Jacq., A. glabrata Jacq., A. laevis Thunb., A. leucanthemoides Jacq., A. maximilianii Schltr. ex Beauverd, A. pusilla DC., A. revoluta Jacq., A. rosea Jacq., A. squarrosa Jacq., A. venidioides DC., and Venidium aureum DC. Key words: Arctotideae, Arctotidinae, Arctotis, Asteraceae, Compositae, South Africa. Arctotis L. is the largest genus in the subtribe Arctotidinae, comprising approximately 60 to 70 species, and is widely distributed in southern Africa (Karis et al., 2009). The main center of taxonomic diversity of the genus is in the winter rainfall region of southern Africa. The taxonomy of Arctotis is especially chaotic. Some of the many taxonomic and nomenclatural problems have been resolved (McKenzie et al., 2006, 2008a, b; McKenzie & Barker, 2007), but many names are still in need of typification. In preparation for the treatment of Arctotis in the upcoming Conspectus of the Trans-Cape Succulent Karoo Flora of South Africa (Snijman, in prep.), we herein clarify the synonymy and typification of names for nine Arctotis species that occur within the geographic area of southern Africa defined by Ju ¨rgens (1991) as the Succulent Karoo region. This region approximately corresponds to the part of the winter rainfall region that experiences the greatest summer aridity. LECTOTYPIFICATION OF ARCTOTIS ARGENTEA The name Arctotis argentea is usually attributed to Thunberg (1799). However, the name was validly published by Aiton (1789), who recorded the introduction of the species to the Royal Botanic Gardens, Kew, by Francis Masson in 1774. Masson accompanied Thunberg on collecting expeditions into the interior of the Cape colony in 1773 and 1774 (Gunn & Codd, 1981). Although the descriptions for new names published by Aiton (1789) were prepared mainly by D. Solander and edited and amended by J. C. Dryander (Stafleu & Cowan, 1976), under Article 46.7 of the International Code of Botanical Nomen- clature (ICBN; McNeill et al., 2006) the name A. argentea must be attributed to Aiton. A sheet in the Herbarium of the Natural History Museum, London (BM), is annotated in pencil ‘‘Arctotis argentea, Thb.’’ and a label is attached bearing the inscription ‘‘Hort. Kew. 1777—Sem. E Cap. bon. Spei.’’ Thus the specimen was prepared from material cultivated at Kew, and because its preparation post-dates the recorded introduction of A. argentea to Kew in 1774 and precedes publication of the description in Aiton (1789), this sheet is suitable for designation as the lectotype for A. argentea. The specimen is consistent with the morphological descriptions of Aiton (1789) and Thunberg (1799). Arctotis argentea Aiton, Hort. Kew. 3: 273. 1789. TYPE: [South Africa.] Cape of Good Hope: Hort. Kew. Sem. E Cap. bon. spei [Hortus Kewensis semen e Capite bonae spei], 1777, s. coll. (lectotype, designated here, BM). LECTOTYPIFICATION OF ARCTOTIS AURICULATA Arctotis auriculata Jacq. is a robust, showy species from the Namaqualand region of northwestern South Africa. The species was described by Jacquin (1797). A single sheet (W 0006633) in the Naturhistorisches Museum Herbarium, Vienna (W), formerly in the Jacquin Herbarium, is annotated as A. auriculata and was designated the lectotype of this name on the sheet by Tycho Norlindh in 1980, but the typification was never published. The material agrees with the descrip- tion and illustration in Jacquin (1797) and is herein formally designated the lectotype of A. auriculata Jacq. NOVON 20: 298–302. PUBLISHED ON 13 SEPTEMBER 2010. doi: 10.3417/2009031