Coreopsideae is a tribe of flowering plants belonging to the Asteroideae subfamily.[1] It includes widely cultivated genera such as Coreopsis, after which the tribe is named, as well as Cosmos and Dahlia.
A similar group has been recognized since 1829, generally as part of the tribe Heliantheae (Cassini, 1819).[2] In the late 20th century, molecular studies caused a slightly redefined version of this group to be recognized as its own tribe, Coreopsideae.[2] The larger version of Heliantheae was split into tribes including Bahieae, Chaenactideae, Coreopsideae, Helenieae and, finally, Heliantheae (sensu stricto).[3] Within the tribe, the traditional definition of genera based on flower and fruit characters does not reflect evolutionary relationships as inferred through molecular phylogenetics.[4]
The tribe is characterized by shiny green bracts at the base of the flower head in two rows: an inner row of tightly spaced bracts and an outer row of a smaller number pointing downward.[5] It includes five genera that use C4 carbon fixation: Chrysanthellum, Eryngiophyllum, Glossocardia (including Guerreroia), Isostigma, and Neuractis. These genera are thought to share a common ancestor and thus a single origin of C4 carbon fixation.[6]
Genera
The 26 Coreopsideae genera recognized by the Global Compositae Database as of April 2022:[7]
^ abRyding, Olof; Bremer, Kare (1992), "Phylogeny, Distribution, and Classification of the Coreopsideae (Asteraceae)", Systematic Botany, 17 (4): 649–659, doi:10.2307/2419733, JSTOR2419733
^Klaus Kubitzki, Joachim W. Kadereit, Charles Jeffrey; The Families and Genera of Vascular Plants
^Rebecca T. Kimballa, Daniel J. Crawford (2004), "Phylogeny of Coreopsideae (Asteraceae) using ITS sequences suggests lability in reproductive characters", Molecular Phylogenetics and Evolution, 33 (1): 127–139, doi:10.1016/j.ympev.2004.04.022, PMID15324843
^Kellogg, E.A. (1999). "Phylogenetic aspects of the evolution of C4 photosynthesis". In Sage, R.F.; Monson, R.K. (eds.). C4 plant biology(PDF). San Diego, CA: Academic Press. pp. 411–444. ISBN0126144400. Retrieved 2018-05-26.
^"Coreopsideae Lindl". Global Compositae Database. Compositae Working Group (CWG). Retrieved 2022-04-04.