Martin and Hutchins 1980, New Mexico Rare Plant Technical Council Website (Sivinski 1997)

Duration: Perennial Nativity: Native Lifeform: Forb/Herb General: Perennial herbs, 20-30 cm tall, from a branching woody caudex; stems erect or spreading, white when mature, covered with barbed hairs or nearly glabrous. Leaves: Alternate along the stems; blades linear, 3-10 cm long, usually with a few rounded teeth or lobes; surfaces scabrous-glochidate (covered with barbed hairs). Flowers: Pale yellow and showy, on pedicels in leaf axils and on branch tips; sepals and petals attached to the top of the ovary (epigynous); sepals 5, narrow and pointed, about 1 cm long; petals 5, pale lemon-yellow, about 2 cm long; outer series of stamens have enlarged filaments, making them look like another set of petals. Fruits: Capsules campanulate- cylindroid (cylindric but slightly broader at the top), about 1 cm long; seeds winged. Ecology: Found in limestone and gypsum soils, from 5,000-6,500 ft (1524-1981 m); flowers May-July. Distribution: central to south-central New Mexico Notes: This taxon is not well resolved. It grades into several other gypsum-loving Mentzelia spp in the region: M. humilis (endemic to se NM), M. saxicola (endemic to w TX near El Paso), and M. multiflora var. integra (possibly endemic to sw UT and nw AZ near Virgin River). For more information, see Bob Sivinski's write-up on the NM Rare Plant Technical Council website, in the section entitled "Species Considered, but Dropped." Look for a perennial with white stems; long narrow leaves which can be nearly entire but usually have at least a few short rounded lobes; showy, pale lemon-yellow flowers with narrow petals about 2 cm long (M. humilis has white flowers but intermediates between the two species are abundant); and short seed pods. Mentzelia is a notoriously difficult genus with an overwhelming number of species and the keys are not easy to use. It is important to make collections with mature seed pods, because many key characters deal with the seeds and capsules, and some can't be seen with a hand lens in the field. Ethnobotany: Unknown, but other species in the genus have uses. Etymology: Mentzelia is named for Christian Mentzel (1622-1701), a German botanist, botanical author and physician; perennis means perennial. Editor: AHazelton 2017