Eriastrum eremicum (Jepson) Mason
Family: Polemoniaceae
desert woollystar,  more...
Eriastrum eremicum image

PLANT: Annual 5-30 cm tall, erect, with several branches.

LEAVES: subglabrous to sparsely villous and viscid, entire to pinnately lobed, with 1-3 pairs of lateral lobes, 1-5 cm long.

CALYX: 5-7 mm long; corolla slightly zygomorphic, with 3 dorsal lobes and 2 ventral lobes, the tube and throat 6-14 mm long, often twice the length of the calyx, the lobes 4-8 mm long, the throat yellow, the lobes bright blue to bluish lavender; stamens inserted near the base of the throat, about equal to the length of the lobes, exserted and often bent upward; pistil 12-15 mm long; style included in the throat to slightly exserted.

CAPSULE: 3-5 mm long.

NOTES: Washes, bajadas, desert shrublands and woodlands: Cochise, Gila, Graham, La Paz, Maricopa, Mohave, Pinal, Yavapai, Yuma cos; 1000-4500 ft; Mar-Jun. s CA to sw UT, s to n MEX. This species includes subsp. yageri (M. E. Jones) H. L. Mason, with slightly zygomorphic, bright blue corollas. This is the common subspecies throughout much of AZ, but the differences from typical subsp. eremicum, which has more lightly colored, zygomorphic corollas, are apparently gradual over a broad geographical gradient extending into CA and s NV.

REFERENCES: Dieter H. Wilken and J. Mark Porter, 2005, Vascular Plants of Arizona: Polemoniaceae. CANOTIA 1: 1-37.

Wilken and Poerter 2005, Kearney and Peebles 1969, McDougall 1973

Duration: Annual

Nativity: Native

Lifeform: Forb/Herb

General: Small annuals 5-30 cm tall with erect stems, sometimes suffrutescent and diffusely branching, the leaves and stems puberulent to lanate.

Leaves: Alternate, linear and entire or pinnately parted near the base with 1-3 pairs of narrow lobes, 1-5 cm long.

Flowers: Bright blue to white, the corolla regular to irregular, calyx 5-7 mm long, the lobes often nearly equaling the tube, the tube and throat 6-14 mm long, flowers borne in dense heads with leafy bracts, these conspicuously cobwebby with long, fine, white hairs, calyx lobes unequal, bristle-tipped, stamens exserted.

Fruits: Capsules 3-5 mm long, ellipsoid to ovoid, seeds 1-several.

Ecology: Found on dry plains, washes, desert shrub and woodlands and mesas, from 5,000 ft or below, (1524 m); flowering March-June.

Notes: Distinguished from E. diffusum by the longer corolla the subequal lobes and the longer anthers.

Ethnobotany: Used as a stomach medicine, for diarrhea, for children with tuberculosis.

Etymology: Eriastrum is form Green erion, for wool and astrum, star, meaning woolly with starlike flowers, while eremicum means of deserts.

Synonyms: None

Editor: SBuckley, 2010, LCrumbacher 2011