Asteroideae is said to date back to approximately 46–36.5 million years ago.[3]
Common characteristics
This family will often have radiate style heads but some could have discoid or disciform. They contain ray florets that are three lobed and are also considered perfect flower implying that it is bisexual. Many contain stigmatic surfaces that are separated by two marginal bands and terminal sterile appendages with sweeping hairs.[4]
Taxonomy
This subfamily is composed of 21 tribes that are broken into 3 supertribes: Senecionodae, Asterodae, and Helianthodae. Senecioneae contains about 120 genera and more than 3,200 species that are found in more temperate areas.[5] Asterodae contains many economically important plants such as the chrysanthemums, common daisy, and the asters. The third super tribe is the Helianthodae, which is the largest of the three, containing 16 of the 21 tribes.[6]
Since 2004, the 21 tribes have been grouped into three supertribes:[2][7][8]
^Harold Robinson; Edward Schilling; José L. Panero. "Eupatorieae"(PDF). p. 14. Retrieved 20 October 2012.
^Fernandez, I (2001), "A Phylogenetic Analysis of Doronicum (Asteraceae, Senecioneae) Based on Morphological, Nuclear Ribosomal (ITS), and Chloroplast (trnL-F) Evidence", Molecular Phylogenetics and Evolution, 20 (1): 41–64, CiteSeerX10.1.1.331.4339, doi:10.1006/mpev.2001.0954, PMID11421647
^Anderberg, A (2005), "Evolutionary relationships in the Asteraceae tribe Inuleae (incl. Plucheeae) evidenced by DNA sequences of F; with notes on the systematic positions of some aberrant genera", Organisms Diversity & Evolution, 5 (2): 135–146, doi:10.1016/j.ode.2004.10.015