Wright’s Thimblehead Hymenothrix wrightii
Family: Asteraceae
Perennial plant (can sometimes act as an annual) growing to about 2’ tall and wide, sometimes taller, with finely textured leaves and white flowers June through October. Reseeds readily.
Full to part sun, moderate water, probably hardy to at least 0°F.
Flowers attract multitudes of butterflies, bees, hummingbirds, and other species of nectar-seeking insects. Where this plant is native, it is a very important nectar source for butterflies and native bees in particular. Larval host for the Dainty Sulfur (Nathalis iole). Seeds utilized by granivorous birds like goldfinches.
Photo by Max Licher, SEINET
Hymenothrix wrightii on iNaturalist
There are 12 species of Hymenothrix native to the southwestern United States and northern Mexico. The genus name, Hymenothrix, comes from Greek hymen, meaning membrane and thrix, bristle, while the species name, wrightii, is named for Charles Wright (1811-1885) an American botanical collector.
There is a very similar species of Hymenothrix that is usually found more north of us in southern Arizona, Loomis' Thimblehead (Hymenothrix loomisii). Good indicators for this species besides the more northerly distribution are the incurved-puberluent petioles and the short lobes of the disk corollas, which are about as long as the throats.
Found in rocky sites, often in dry sites from 3,000-7,500 ft. in Arizona, New Mexico, Sonora, with scattered populations in California, Baja California, and Chihuahua.
Typical growth form, photo by Max Licher, SEINET
Foliage before the plants begin to bloom, photo by Lindsay Willrick, iNaturalist
Seed details, photo by Ken-ichi Ueda, iNaturalist
Flower details of a very similar species, Hymenothrix loomisii, photo by wingedchimera on iNaturalist