Plant: annual herb; to 60 cm tall Leaves: to 15 cm long, sessile, elliptic to lanceolate; margin toothed to pectinately lobed. BRACTS ovate to lanceolate or triangular, green, mostly not on ovary; margins few-toothed to entire INFLORESCENCE: cymose Flowers: sessile; petals yellow, 8-20 mm long, (3-)5-10 mm wide; staminodia 0; stamens ca. 30-50, all with linear filaments; style 5-10 mm long Fruit: capsules clavate, long-tapering to base; base not woody; body 20-38 mm long, S-shaped or arching to 180 degrees. SEEDS pendulous, not winged, those in upper half of capsule grain-like, several-faceted, irregular in cross-section, the angles sharp; testa cells with straight adjoining walls, the surface wall pointed-papillate Misc: Deserts to low chaparral; 200-1300 (-1600) m (600-4200 (-5300) ft); Jan-Jun Notes: capsules are s-shaped, arching 180 degrees.Leaves are pectinately toothed and surface is rough pubescent. References: Hickman, ed., The Jepson Manual. Christy, Charlotte M.; Loasaceae, Journal of the AZ-NV academy of Science.

Christy 1998, Jepson 1993, Kearney and Peebles 1969, McDougall 1973

Duration: Annual Nativity: Native Lifeform: Vine General: Annual with slender white stems, generally sprawling, to 60 cm tall, the stems shining, glabrous to pubescent, hairs of the vegetation cause the plant to stick to clothing, although the hairs are not stinging. Leaves: Blades sessile, deeply pinnatifid, 10-14 cm long, thick, the upper ones few-toothed or entire. Flowers: Yellow, axillary, sessile, solitary, or in small clusters, petals 6-22 mm, stamens shorter than the petals, bracts triangular-ovate, entire. Fruits: S-shaped or curved, arching to 180 degrees, 15-38 mm long, with an inflated tip 2-4 mm in diameter, seeds square and irregularly angled, seeds not grooved on the angles. Ecology: Found in sandy soils, in washes and on plains, from 1,500-5,500 ft (457-1676 m); flowering March-June. Notes: Look for this species under Mentzelia nitens var. jonesii. The main difference between Mentzelia nitens and Mentzelia jonesii is the capsule size and flower size of M. jonesii, but other differences are difficult to determine, and care should be taken when identifying these species. Mentzelias are tricky; please note that mature fruits and seeds are nearly always necessary for ID. Ethnobotany: There is no specific use of the species recorded, but the genus was used as a food source, the seeds were ground, parbroiled, or parched and stored for later use. Etymology: Mentzelia is named for Christian Mentzel or Christianus Mentzelius (1622-1701), a 17th century German botanist, while jonesii is named after Marcus Eugene Jones (1852-1934), a self-taught geologist and botanist. Synonyms: None Editor: LCrumbacher, 2011