Asteroideae


Asteroideae is a subfamily of the plant family Asteraceae. It contains about 70% of the species of the family. It is made of several tribes, including Astereae, Calenduleae, Eupatorieae, Gnaphalieae, Heliantheae, Senecioneae and Tageteae. Asteroideae contains plants found all over the world, many of which are shrubby. There are about 1,135 genera and 17,200 species within this subfamily; the largest genera by number of species are Helichrysum and Artemisia. Asteroideae is said to have begun approximately 46-36.5 million years ago.

Tribes

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 3200 species that are found in more temperate areas. 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.

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.

Uses

The subfamily Asteroideae has many genera within the tribes that have economic uses. The Helianthus tuberosus, Helianthus annuus, Guizotia abyssinica are all used as oil seed crops. Artemisia dracunculus is used for culinary herb and Parthenium argentatum is a rubber source. Some of the other genera are used as ornamentals; those are Dendranthema spp., Callistephus, Cosmos, Tagetes, and many others.

Classification

Since 2004, the 21 tribes have been grouped into three supertribes: