Annual, Perennial, Herbs, Taproot present, Nodules present, Stems erect or ascending, Stems less than 1 m tall, Stems solid, Stems or young twigs glabrous or sparsely glabrate, Stems or young twigs sparsely to densely hairy, Stems with hooked uncinate hairs or prickles, Leaves alternate, Leaves petiolate, Stipules conspicuous, Stipules green, triangulate to lanceolate or foliaceous, Stipules free, Leaves simple, or appearing so, Leaves compound, Leaves pinnately 3-foliolate, Leaves odd pinnate, Leaf or leaflet margins enti re, Leaflets opposite, Stipels present at base of leaflets, Leaflets 1, Leaflets 3, Leaves hairy on one or both surfaces, Inflorescences racemes, Inflorescence axillary, Inflorescence terminal, Bracts very small, absent or caducous, Bracteoles present, Flowers zygomorphic, Calyx 2-lipped or 2-lobed, Calyx hairy, Petals separate, Corolla papilionaceous, Petals clawed, Petals blue, lavander to purple, or violet, Banner petal ovoid or obovate, Wing petals narrow, oblanceolate to oblong, Wing tips obtuse or rounded, Keel tips obtuse or rounded, not beaked, Stamens 9-10, Stamens diadelphous, 9 united, 1 free, Filaments glabrous, Style terete, Fruit a loment, jointed, separating into articles, Fruit unilocular, Fruit indehiscent, Fruit elongate, straight, Fruit exserted from calyx, Fruit compressed between seeds, Fruit hairy, Fruit 3-10 seeded, Seeds ovoid to rounded in outline, Seeds reniform, Seed surface smooth, Seeds olive, brown, or black.
Duration: Annual Nativity: Native Lifeform: Forb/Herb General: Erect or ascending, moderately to much branched, annual forb 10-45 cm tall, stems and branches slender but deeply grooved, terete or subangulate, sparsely to densely uncinate-puberulent. Leaves: Stipules slenderly linear-lanceolate, attenuate, 1.5-6 mm. long, minutely striate, glabrous above and below but ciliate-hispid along margins. Petioles slender, grooved, .5-5 cm long; leaflets 3, linear-lanceolate to ovate, obtuse and mucronulate at apex, 2-21 mm wide, 1.5-6 cm long, terminal ones similar in shape, light green and sparsely strigose to glabrate above, slightly paler and sparsely strigose beneath. Flowers: Inflorescence 10 cm long, pedicels filiform, 7-12 mm long, calyx small, purplish-pink to white, about 2-2.5 mm long, corolla about 2.5-3 mm long. Fruits: Loment 2-5 jointed, sessile or faintly stipitate, joints rhomboidal, reticulate and uncinate-hispidulous, 2.5-3 mm wide, 3-4 mm long, margins slightly folded or revolute, terminal joint slightly larger than others. Ecology: Found on mountainsides, mesas, canyons and grassy slopes from 3,500-6,000 ft (1067-1829 m); flowers July-September. Ethnobotany: Many non-regional medicinal uses for other species. Etymology: Desmodium might come from the Greek desmos meaning bond, fastening or chain, referring to the loment, while neomexicanum means New Mexico where the type was found in the late 1800s. Synonyms: Meibomia neomexicana Editor: SBuckley, 2010