The photo at right shows a close-up of the inflorescence of white-stemmed mentzelia as seen on slopes above Girds Creek Rd at the eastern base of Sutton Mt. to the south of the John Day River in central Oregon.........April 8, 2007.
White-stemmed mentzelia is an annual wildflower with simple to freely branched stems from 10-40 cm high. The stem is often glabrous below but becomes white and shining above. The hairs are often minutely barbed. The leaves measure from 2-10 cm long with the basal leaves typically linear to lanceolate in shape with entire to shallowly few-lobed to deeply pinnatifid margins narrowing gradually to the petioles. The stem leaves are linear to lanceolate with subentire to irregularly lobed margins.
The inflorescence consists of open, few-flowered cymes at the ends of the branches. The calyx is 1-2 cm long with short, triangular lobes from 2-4 mm long. The yellow petals are 2-6 mm long and often copper-colored at their base. The 15-35 stamens are shorter than the petals. The capsules are 10-14 mm long, covered with firm, stiff hairs and are narrowed toward the base.
White-stemmed mentzelia may be found on dry, sandy soils in the desert valleys and foothills.
White-stemmed mentzelia may be found to the east of the Cascade and Sierra Nevada Mts. from British Columbia south to southern California and east to Montana and New Mexico.
