Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

Home to the plants of the Sonoran, Chihuahuan and Mojave Deserts

Cirsium ochrocentrum, Yellowspine Thistle

Asteraceae or Compositae Family
Aster, Daisy, Composite and Sunflower Family

The Asteraceae or Compositae are commonly known by several names including the Aster, Daisy, Composite and Sunflower Family. This is one of the largest families with a worldwide distribution. Asteraceae has 12 subfamilies each with their own characteristics. Depending of the source, the Asteraceae are second in size only to the Orchidaceae. Part of the confusion is related to the fact that it is difficult to know with any certainty how many species are in each family.

Asteraceae members have a major characteristic, a capitula (head) surrounded by involucral bracts or phyllaries. The type genus is Aster which is the reason for one of the common names. The original family name of Compositae is a reference to the composition of "florets" on the head which in total make up the complete visible "flower".

Members of this family have major economic and ecologic significance. They are present from the Polar Regions to the tropics thriving in most or all available habitats. Plants here are mostly Forb/herbs herbaceous but shrubs, vines and trees are also represented. With a cosmopolitan distribution Asteraceae are more common in arid and semiarid areas within subtropical and lower temperate latitudes.

Species of significant economic value as food products include; lettuce, sunflower seeds, artichokes, sweetening agents, coffee substitutes and herbal teas. Other members are important to the agricultural and horticultural industry including; Marigold, Calendula Cone Flowers, Daisies (many species) Fleabane, Chrysanthemums, Dahlias, Zinnias and Heleniums. Of herbal importance are members of the genera Grindelia, Echinacea and Yarrow. In spite of these outstanding members, perhaps of equal importance are the invasive weedy species and species that cause or worsen allergies.

The Plant List includes 32,913 accepted species names for the family Compositae (=Asteraceae) and a further 32,205 scientific plant names of infraspecific rank.

References: , updated 03/23/2017
The Plant List. A working list of all known plant species. (accessed; 04/05/2015), updated 03/23/2017
Wikipedia contributors, 'Asteraceae', Wikipedia, The Free Encyclopedia, 24 March 2015, 03:47 UTC, [accessed 5 April 2015]
U.S. Dept. of Agriculture, Natural Resources Conservation Service on-line database – ITIS search