|
''Alvordia'' is a genus of flowering plants in the family Asteraceae. It includes 4 species of shrubs which occur in the states of Baja California and Sonora, Mexico. The genus is characterized by having a secondary clustering of heads into compound units, so that what appears to be a single head is actually a group of heads packed together.〔Carter, A. M. 1964. The genus ''Alvordia'' (Compositae) of Baja California, Mexico. Proceedings of the California Academy of Sciences 30: 157-174.〕 The genus is classified as a member of subtribe Helianthinae, the same subtribe that contains the common sunflower (''Helianthus''). Based on the reported chromosome counts, ''Alvordia'' includes both diploid and polyploid species, but the relationships among these have not yet been studied in detail. No chromosome count has yet been reported for the species ''A. congesta'' from Sonora, which was a later transfer to the genus.〔Turner, B. L. 1988. Reduction of the Mexican genus ''Agiabampoa'' to ''Alvordia'' (Asteraceae, Heliantheae). Phytologia 64: 209-210.〕 The genus is endemic to northwestern Mexico, known from the 3 states of Sonora, Baja California, and Baja California Sur.〔Shreve, F. & I. L. Wiggins. 1964. Vegetation and Flora of the Sonoran Desert 2 vols. Stanford University Press, Stanford〕 ;Species〔(The Plant List, search for ''Alvordia'' )〕 # ''Alvordia brandegeei'' A. M. Carter - Baja California Sur # ''Alvordia congesta'' (Rose ex Hoffm.) B. L. Turner - Sonora # ''Alvordia fruticosa'' Brandegee - Baja California, Baja California Sur # ''Alvordia glomerata'' Brandegee - Baja California Sur # ==References== 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「Alvordia」の詳細全文を読む スポンサード リンク
|