The Genus Dalea
Family: Fabaceae
This is a large genus of about 205 species commonly known as prairie clovers or indigo bushes. They are native to the Western hemisphere, where they are distributed from Canada to Argentina. Nearly half of the known species are endemic to Mexico. Listed here are the herbaceous Dalea species (the shrubby species are listed in the shrub section).
Daleas are great nectar plants for butterflies in particular. They are also larval host plants for the Reakirt’s blue (Echinargus isola), southern dogface (Zerene cesonia), and the gray hairstreak (Strymon melinus).
Many dalea species are used for medicine. Also, many species are used as enjoyable teas.
The genus, Dalea, honors English apothecary Samuel Dale (1659–1739).
Whiteflower Prairieclover
Dalea bicolor
This herbaceous perennial grows to about 2-3’ tall and wide. White flowers can appear anytime during the warm season which attract loads of butterflies, bees, and other nectar feeders.
Cut back after blooming season, when they look like they need it. Full to part sun, moderate to regular water, probably hardy to at least 0°F.
The species, albiflora, means white flowered. A similar species, the white prairie clover (Dalea candida), is a little more upright.
Found on open slopes often in canyons from 3,500-7,000 ft. in Arizona, southwestern New Mexico; south into northern Mexico.
Lemon Dalea
Dalea capitata
Usually an evergreen groundcover in Tucson, lemon dalea grows about 1’ tall or less and spreads at least 3’ wide, sometimes more. Yellow flowers appear in warm weather.
Grow in full to part sun, with moderate water, hardy to 0° F.
From Central Mexico.
Pringle's Prairie Clover
Dalea pringlei
Upright growing perennial growing to about 2’ tall. Purple flowers with prominent yellow stamens occur in warm weather.
Full to part sun, moderate to regular water, hardy to about 0°F or colder.
The species name, pringlei, is named for Cyrus Guernsey Pringle (1838-1911) an American plant collector.
Found on slopes from 2,500-5,000 ft. in Arizona, Sonora, and just getting into a few other neighboring regions.
Purple Prairie Clover
Dalea purpurea
Easily grown in average, medium, well-drained soils. Thick and deep taproot enables this plant to tolerate drought well. May self-seed in optimum growing conditions. Typically grows 1-3' tall. Features tiny purple flowers in dense, cone-like heads (to 2" long) atop erect, wiry stems in summer. Compound, odd-pinnate leaves, with 3-5 narrow linear leaflets. A nitrogen-fixing plant.
Part sun to bright shade. Moderate water. Ridiculously cold hardy since it also occurs far north of Arizona.
Formerly known as Petalostemon purpureum. The species, purpurea, means purple referring to the flowers.
Found in grasslands, from 4,000-7,500 ft. From Canada, south through the midwestern United States, into the southern and southwestern United States, including throughout Arizona, and just a smattering of Sonoran populations.