Palmer’s cleomella, Rocky Mountain stinkweed

Cleomella cornuta Rydberg; C. montrosae Payson; C. nana Eastwood

Plants 10-38 cm. Stems usually sparsely branched proximally (without a dominant central stem); glabrous. Leaves: stip-ules 3-5-fid, (larger, more conspicuous in inflorescences), 0.5-1.5 mm (scarious); petiole 0.4-2(-2.7) cm; leaflet blade narrowly oblong-elliptic, 0.8-2.6 × 0.1-0.8 cm, thin, margins entire, apex obtuse to retuse, mucronulate, surfaces glabrous. Inflorescences corymbs or racemes, terminating stems, 1-2 cm (2-3.5 cm in fruit); bracts ± rudimentary. Pedicels slightly ascending in fruit, 6-7 mm (7-11 mm in fruit). Flowers: sepals green, deltate, 1-1.5 × 0.5-0.6 mm, glabrous; petals yellow, oblong, 3-5 × 1-1.3 mm, glabrous; stamens (well-exserted), yellow, 7-9 mm; anthers 1.4-1.6 mm; gynophore spreading, 2.5-6(-8) mm in fruit; ovary obovoid, 1.3-1.5 mm; style 0.7-1 mm. Capsules rhomboidal (widest distal to midpoint), 2-5 × 3-5(-6.5) mm, glabrous. Seeds (1 or) 2-4(-7), stramineous becoming black, globose, 2-2.5 mm, smooth.

Flowering spring-early fall. Dry open alkaline, gravelly or sandy flats; 1100-2000 m; Ariz., Colo., N.Mex., Utah.