Herbs or subshrubs, multi-stemmed, often loosely mat-forming to 2.5 dm diam., 0.1–0.5 dm. Stems prostrate to laxly erect, glabrous or very sparsely pubescent, hairs incurved. Leaves sessile or subsessile; blade elliptic, obovate, ovate, or scalelike, (1.5–)2–5.9(–8) × 0.8–3.5 mm, base cuneate or rounded, apex acute, surfaces sparsely pubescent to subglabrous, hairs incurved. Racemes terminal, sometimes appearing axillary (from branches proximal to racemes of major branches with vegetative portions highly reduced), reduced to 1–3(–5) flowers, 0.5–1 × 0.7–1.9 cm; peduncle 0–0.2 cm; rachis not thorn-tipped; bracts persistent, ovate, lanceolate, or linear. Pedicels (0.6–)1–3(–3.6) mm, usually glabrous, rarely sparsely pubescent. Flowers pink or purple with pale margins, keel sometimes cream, distally greenish yellow, (2.4–)2.9–5.1(–5.4) mm; sepals: lateral ones deciduous, elliptic, ovate, or obovate, (1.2–)1.6–3(–3.2) mm, upper sepal persistent, ovate, (1–)1.2–2.4 mm, glabrous, margins sometimes sparsely ciliate proximally; wings obovate, (2.2–)2.5–4.6(–5.1) × 1.8–2.8 mm, glabrous or sparsely pubescent proximally; keel (1.7–)2.3–3.6 mm, sac incurved-puberulent in distal 1/2, beak obscure, deltate, bluntly rounded, or linear to oblong, (0–)0.1–0.7 × (0–)0.1–0.5 mm, glabrous. Capsules ellipsoid-obovoid, sometimes broadly so, 1.9–3.6 × 1.6–2.9 mm, base cuneate to rounded, margins narrowly and evenly winged or slightly expanded apically, glabrous or sparsely pubescent apically. Seeds (1.7–)1.9–3.2 mm, body, excluding aril and pubescence, 1–1.9 mm, densely pubescent; aril (0.3–)0.4–0.7 mm, lobes often highly reduced, nearly absent to 1/6 length of seed.

Discussion

Varieties 2 (2 in the flora): sw, sc United States.

Selected References

None.

Lower Taxa

Rhinotropis rimulicola var. mescalerorum, Rhinotropis rimulicola var. rimulicola

Key

1	Keel petals with deltate or rounded beaks (often obscure), (0–)0.1–0.3(–0.5) mm, base width equal to or greater than length; seeds (1.7–)1.9–2.7 mm; sepals eciliate or, infrequently, with a few proximal cilia.	Rhinotropis rimulicola var. rimulicola
1	Keel petals with linear to oblong beaks, 0.3–0.7 mm, base width usually less than 2/3 length; seeds 2.8–3.2 mm; sepals sparsely ciliate in proximal 1/2.	Rhinotropis rimulicola var. mescalerorum