Glossopetalon spinescens var. microphyllum
Brittonia 40: 272, fig. 1i – l. 1988.
Shrubs, 25–60 cm. Branchlets divaricate to ± ascending, usually turning from grayish green to dull orangish brown toward end of 1st year, (sometimes later), glabrous or ciliolate. Leaves usually well developed at flowering, sometimes early deciduous, branches sometimes appearing nearly leafless later in growing season; stipules present, sometimes difficult to observe, adnate portion dark reddish purple to nearly black, usually well developed, noticeably thickened, free portion usually relatively well developed, mostly narrowly triangular to subulate, 0.4–1.2 mm; largest blade 3–7 (–8) × 1.2–2.7 mm, margins glabrous or ciliolate, glabrous. Petals 4–8 mm, mostly widest proximal to apex sometimes nearly oblong, apex rounded to gradually acute or acuminate, tips blunt or sharply pointed. Stamens 6–10 in 2 unequal series.
Phenology: Flowering Apr–Jun.
Habitat: Rocky margins of washes, steep rocky hillsides, crevices and ledges of cliffs and outcrops, mostly on limestone substrates
Elevation: 1300–2400 m
Ariz., Nev., Utah.
A single collection from San Bernardino County, California (Davidson, Gustafson & Reynolds 7853 [MO, RSA]), compares well with specimens from the main range of var. microphyllum in its small leaves, divaricate branching, and orangish brown older branchlets, but appears to differ in being a somewhat taller plant with the twigs changing color more tardily and the leaves moderately puberulent (versus glabrous) abaxially. Further studies may confirm a disjunct range extension for this variety in eastern California.
"widest" is not a number.