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''Gazania'' 〔''Sunset Western Garden Book,'' 1995:606–607〕 is a genus of flowering plants in the family Asteraceae, native to Southern Africa.〔(Gaertner, Joseph. 1791. De fructibus et seminibus plantarum 2(3): 451–452 ) in Latin〕〔(Gaertner, Joseph. 1791. De fructibus et seminibus plantarum 2(3): plate CLXXIII (173) ) line drawing of ''Gazania rigens''〕〔〔Per Ola Karis. 2007. "Arctotideae" pages 200-207. In: Klaus Kubitzki (series editor); Joachim W. Kadereit and Charles Jeffrey (volume editors). ''The Families and Genera of Vascular Plants'' volume VIII. Springer-Verlag: Berlin; Heidelberg, Germany.〕 They produce large, daisy-like composite flowers in brilliant shades of yellow and orange, over a long period in summer. They are often planted as drought-tolerant groundcover. ==Taxonomic history== The genus was first formally described by German botanist Joseph Gaertner in the second volume of his major work ''De Fructibus et Seminibus Plantarum'' in 1791.〔 Gaertner named the genus after Theodorus Gaza, a 15th-century translator of the works of Theophrastus.〔Seranne Howis, Nigel P. Barker, and Ladislav Mucina. 2009. "Globally grown, but poorly known: species limits and biogeography of ''Gazania'' Gaertn. (Asteraceae) inferred from chloroplast and nuclear DNA sequence data". ''Taxon'' 58(3):871-882.〕 ''Gazania'' is a member of the tribe Arctotideae and the subtribe Gorteriinae. Within the subtribe it is close to ''Hirpicium'' and ''Gorteria''.〔Vicki A. Funk and Raymund Chan. 2008. "Phylogeny of the Spiny African Daisies (Compositae, tribe Arctotideae, subtribe Gorteriinae) based on ''trn''L-F, ''ndh''F, and ITS sequence data". ''Molecular Phylogenetics and Evolution'' 48(1):47-60.〕 Many of the species of ''Gazania'' are hard to distinguish and the number of species assigned to the genus has varied widely from one author to another. In 1959, Helmut Roessler published what he considered to be a preliminary revision of ''Gazania''. At that time, he recognized 16 species.〔Helmut Rössler. 1959. "Revision der Arctotideae - Gorteriinae (Compositae)". ''Mitteilungen der Botanischen Staatssammlung München'' 3:71-500.〕 Roessler published some amendments to his treatment in 1973.〔Helmut Roessler. 1973. ''Mitteilungen der Botanischen Staatssammlung Muenchen'' 11:91-99.〕 In 2009, a phylogeny of the genus was published. It was based on molecular phylogenetic analysis of chloroplast and nuclear DNA sequences.〔 In this study, all of Roessler's species except ''Gazania othonnites'' were sampled. The authors found that eight species were not really separate, but formed a species complex. The seven species found to be distinct were ''G. jurineifolia, G. caespitosa, G. ciliaris, G. tenuifolia, G. heterochaeta, G. schenckii,'' and ''G. lichtensteinii''. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「gazania」の詳細全文を読む スポンサード リンク
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