One family of plants currently is known as the Asteraceae, but for many years was called the Compositae. It's a huge family that includes such plants as sunflowers, daisies, and goldenrod. Many people are now aware that what we think of as the flower actually is composed of a large number of flowers, which is what led to the name Compositae. The bright yellow "petals" of a sunflower, for example, are separate flowers, each with a single large petal, while the disk of the sunflower is made up of a large number of flowers, none of which has prominent petals.
The composites are not the only plants to put together separate flowers
in such an arrangement as to suggest a single blossom. A number of legumes—plants
belonging to the pea family—have aggregates of flowers that may appear to be a single
one to the uninitiated. Mimosas, mesquites, and fairy dusters belong to this group—a
group with flowers so distinctive from other legumes that it sometimes is placed in a
separate family, the Mimosaceae, the mimosa family.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.
What appear to be two Fairy Duster flowers in the foreground actually are two clusters of flowers. Photograph by Wynn Anderson.