PLANT : Broom-like subshrubs up to 1 m tall; stems yellow-green, canescent, prominently dotted with pale yellow glands.

LEAVES : simple (rarely 3-foliate), linear, 70-110 mm long, 0.8-1.2 mm wide; glands in two rows along the margin.

FLOWERS : in a short, dense raceme; calyx teeth 0.3-1.8 mm long, much shorter than tube.

FRUIT : ca. 4 mm long, pilose, with glands near apex.

NOTES : Sandy dunes and washes: Cochise, Coconino, Navajo cos. (Fig. 2C); 1100-1550 m (3600-5000 ft); Jul-Sep; NM, TX.

REFERENCES : Rhodes, Suzanne, June Beasley and Tina Ayers. 2011. Fabaceae. CANOTIA 7: 1-13.

Common Name: broom dalea

Duration: Perennial

Nativity: Native

Lifeform: Shrub

General: Unarmed shrubs, to 1 m tall or more; stems much branching with a broom-like growth form; stems and branches yellow-green and copiously covered with amber-colored glands; smaller branchlets also canescent with white hairs.

Leaves: Alternate, sparse, and early-deciduous; blades linear, 5-20 mm long and 1-2 mm wide, with a row of glands along each edge; rarely leaves will be tri-foliate, with 3 linear leaflets.

Flowers: Purple, in small rounded clusters, about 1 cm wide, at branch tips; flowers 8-10 mm long, with pea-flower morphology (papilionaceous); sepals 5, white-hairy, fused at the base into a tube 3-4 mm long, topped with 5 short teeth; petals blue to violet, 6-9 mm long.

Fruits: Pods hairy and glandular, about 4 mm long, about 2/3 hidden within the calyx; containing 1-2 seeds.

Ecology: Found in deep sand and washes, from 3,500-5,000 ft (1067-1524 m); flowers June-September.

Distribution: w TX, NM, e AZ; south to MEX

Notes: Psorothamnus spp. are gland-covered shrubs with small blue-purple pea flowers. P. scoparius is distinguished from others in the genus by its shrubby growth form and lack of spines (P. spinosus is tree-height and has spine-tipped branches); its few, simple and linear, early-deciduous leaves (P. fremontii and P. thompsoniae have more abundant, pinnately compound leaves); and flowers in compact round clusters about 1 cm wide. It has a scattered distribution in the southwest and is especially abundant in the Rio Grande valley in central and southern New Mexcio.

Ethnobotany: Unknown

Etymology: Psorothamnus means warty shrub, from the Greek psora, a scab or wart, and thamnos, shrub, alluding to the gland-covered stems; scoparius means broom-like.

Synonyms: Dalea scoparia

Editor: AHazelton 2017