Eriastrum diffusum

PLANT: Annual 3-35 cm tall, erect and simple to diffusely branching. LEAVES: subglabrous to sparsely woolly, entire or with 1-2 pairs of lobes near the base of the rachis, 1-3 cm long. CALYX: 6-7 mm long; corolla actinomorphic, narrowly funnelform to slightly zygomorphic, the throat white to yellow, the lobes white to pale blue or bluish lavender, the tube and throat 4-7 mm long, slightly longer than the calyx tube, the lobes 3-5 mm long; stamens inserted on the throat near the sinuses, less than the length of the corolla lobes; filaments slightly unequal in length; pistil 5-7 mm long; style included in the tube or throat. CAPSULE: 2-4 mm long. NOTES: Open sites, desert shrublands, sagebrush, pinyon-juniper woodland: Cochise, Gila, Graham, La Paz, Maricopa, Mohave, Pima, Pinal, Santa Cruz, Yavapai, Yuma cos; 700-5600 ft; Feb-Jun. s CA to w CO, s to n Mex. This species includes plants assigned to E. diffusum subsp. jonesii H. L. Mason, with corollas 10-12 mm long and anthers 0.7-1 mm long. The typical, more common subsp. diffusum usually has shorter corollas and anthers less than 0.8 mm long. These differences do not appear correlated with geographical or ecological distribution. REFERENCES: Dieter H. Wilken and J. Mark Porter, 2005, Vascular Plants of Arizona: Polemoniaceae. CANOTIA 1: 1-37.

Wiggins 1964, Wilken and Porter 2005

Duration: Annual Nativity: Native Lifeform: Forb/Herb General: Delicate annual herb, 3-35 cm tall, erect, stems simple to diffusely branching. Leaves: Basal and cauline, the cauline leaves alternate; needlelike and entire or with 1-2 pairs of lobes near the base; 1-3 cm long; subglabrous to sparsely woolly. Flowers: White to blue-purple, sessile in compact terminal clusters subtended by wolly bracts; calyx 6-7 mm long; corolla radially symmetrical, narrowly funnelform to slightly zygomorphic, throat white to yellow, lobes white to pale blue or bluish lavender, entire corolla 6-11 mm long; stamens inserted on throat near sinuses, shorter than corolla lobes, the filaments unequal in length. Fruits: Capsule 2-4 mm long. Ecology: Found in open sites, desert shrublands, sagebrush, and pinyon-juniper woodland, below 5,500 ft (1676 m); flowers February-June. Distribution: s CA, s NV, s UT, AZ, NM, CO, s TX; south to n MEX. Notes: These spring annuals are distinguished by wooly pubescence all over and delicate purple bracteate flower clusters; and from the other Eriastrum by having smaller flowers (corolla 6-11 mm in E. diffusum vs. 12-20 mm in E. eremicum). Ethnobotany: Unknown, but others in the genus have medicinal uses. Etymology: Eriastrum is from Greek erion, for wool, and astrum, star, meaning woolly with starlike flowers; diffusum means diffuse, referring to the plant's branching pattern. Synonyms: Eriastrum diffusum subsp. jonesii Editor: SBuckley 2010, FSCoburn 2015, AHazelton 2015