is a genus of plants in the sunflower family
. They are sometimes called yellowtops
. Some are annual or perennial herbs and some are shrubs. They bear yellow flowers. These plants are found in the Americas, Asia, Africa, and Australia. Some members of this genus exhibit C3 carbon fixation
, while others are C4 plants
and some are intermediate. With closely related species exhibiting different forms of metabolism, this genus has been included in studies on the evolution of photosynthesis. A monograph published by A. M. Powell in 1978 (Systematics of Flaveria (Flaveriinae-Asteraceae) in Annals of the Missouri Botanical Garden) is the most comprehensive study of morphology and biogeography for the Flaveria species to date. A recent phylogenetic study published by A. McKown et al. in 2005 (Phylogeny of Flaveria (Asteraceae) and inference of C4 photosynthesis evolution in American Journal of Botany) clarifies many of the evolutionary relationships between Flaveria species.