PLANTS: Perennials. STEMS: to 50 cm tall, usually producing branches along their entire length. LEAVES: to 8 cm long, to 3 cm wide, sessile, elliptic to lanceolate or linear; margins deeply and narrowly pinnately lobed, sometimes approaching entire and then linear; upper leaves without clasping bases or clasping basal lobes. FLOWERS: pedicellate, subtended by 0-2 linear to lanceolate, entire or lobed bracts, these sometimes fused to ovary; petals yellow, 8-15 mm long, 3-5 mm wide,with trichomes at apex only; staminodia or petaloid stamens 3-5, slightly smaller than petals; outer several whorls of stamens with slightly broadened filaments; style 7-10 mm long; stigmatic papillae inconspicuous. CAPSULES: cylindric, 9-15 mm long. SEEDS: horizontal, winged, oval to obovate; testa cells with wavy adjoining walls, the surface walls with 5-10 small bumps. 2n = 20. NOTES: (not mapped): possibly in e Apache co.; 2000-2200 m (6500-7200 ft); probably Jun-Sep; sw CO, ne NM. This taxon has been collected in NM in the vicinity of Green Knobs (north of Ft. Defiance), ca. 1.5 miles east of the AZ border. These collections have been mistakenly reported as AZ records, both as M. laciniata, and with an incorrect identification, as M. humilis (A. Gray) J. Darl., a similar species that is most common in se NM and w TX, on gypsum. REFERENCES: Christy, Charlotte M. 1998. Loasaceae. J. Ariz. – Nev. Acad. Sci. 30(2): 96.