Isocoma acradenia (Greene) Greene
Family: Asteraceae
alkali goldenbush,  more...
[Bigelowia acradenia ]
Isocoma acradenia image

Herbage usually glabrous, sometimes minutely hispidulous, often stipitate-glandular, often resinous. Leaf blades oblanceolate to narrowly obovate, 20-150 mm, margins entire or toothed or lobed (teeth or lobes apically rounded-obtuse). Involucres 5-8 × 5-7 mm. Phyllary apices yellowish to greenish yellow, sometimes spinulose-aristate, usually not gland-dotted, usually with single, strongly developed, subepidermal resin pocket nearly as wide as bracts, sometimes a central pocket and 2+ smaller, lateral ones (resin pockets sometimes formed from numerous, coalesced, sessile glands). Florets 12-27; corollas 5-7(-8) mm. Cypsela ribs not forming apical horns.

Isocoma acradenia is distinctive in its whitish stems and narrow, whitish-indurate phyllaries with an apical resin pocket (or pockets). The leaves often occur in axillary fascicles.

Varieties 3 (3 in the flora): sw United States, nw Mexico.

FNA 2006, Benson and Darrow 1981, Kearney and Peebles 1969

Common Name: alkali goldenbush

Duration: Perennial

Nativity: Native

Lifeform: Subshrub

Wetland Status: FACU

General: Erect shrub, densely branched 30-100 cm, with mostly ascending, slender, brittle, woody stems; herbage glandular punctate, copiously resinous-glutinous, young herbage with sparse, short, white hairs covered in resin.

Leaves: Oblong to oblanceolate, entire to toothed or lobed to shallowly parted.

Flowers: Involucral bract an apically thickened, wartlike, green area bearing minute dotlike resin glands near tip; phyllaries linear-oblong, margins narrowly transparent-membranous and erose-ciliate at tip; corolla lobes 0.5-0.7 or occasionally 1 mm long, nearly acute, bright yellow, longer than pappus.

Fruits: Ribbed cypselae, moderately to densely pubescent, pappus of many coarse persistent barbellate and uneven bristles.

Ecology: Found on desert slopes, hillsides, and plains below 4,000 ft (1219 m); flowers August-October.

Distribution: s CA, s NV, UT, AZ; south to n MEX.

Notes: Told apart from other Isocoma spp. by the characteristic wartlike resin pocket near tip of phyllaries.

Ethnobotany: Used as a poultice applied to sores, steeped for sore throats, and as a building material.

Etymology: Isocoma is from the Greek meaning an equal hair-tuft, referring to flowers, acradenia is from Greek for pointed-glanded.

Synonyms: Haplopappus acradenius

Editor: SBuckley 2010, FSCoburn 2015