Acmispon denticulatus (Drew) D. D. Sokoloff

Annual, Herbs, Taproot present, Nodules present, Stems erect or ascending, Stems or branches arching, spreading or decumbent, Stems less than 1 m tall, Stems solid, Stems or young twigs glaucous, Stems or young twigs glabrous or sparsely glabrate, Stems or young twigs sparsely to densely hairy, Leaves alternate, Leaves petiolate, Stipules inconspicuous, absent, or caducous, Leaves compound, Leaves palmately 2-3 foliate, Leaves pinnately 3-foliolate, Leaves odd pinnate, Leaf or leaflet margins entire, Leaflets opposite, Leaflets alternate or su bopposite, Leaflets 2, Leaflets 3, Leaflets 4, Leaves glabrous or nearly so, Flowers solitary in axils, or appearing solitary, Inflorescence sessile or subsessile, Inflorescence axillary, Flowers zygomorphic, Calyx 5-lobed, Calyx hairy, Petals separate, Corolla papilionaceous, Petals clawed, Petals ochroleucous, cream colored, Petals pinkish to rose, 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 or anthers dimorphic, alternating large and small, Stamens diadelphous, 9 united, 1 free, Filaments glabrous, Style terete, Style persistent in fruit, Fruit a legume, Fruit unilocular, Fruit freely dehiscent, Fruit elongate, straight, Fruit or valves persistent on stem, Fruit coriaceous or becoming woody, Fruit exserted from calyx, Fruit internally septate between the seeds, Valves twisting or coiling after dehiscence, Fruit glabrous or glabrate, Fruit 2-seeded, Fr uit 3-10 seeded, Seeds reniform, Seed surface smooth, Seeds olive, brown, or black.

Acmispon denticulatus (previously Lotus denticulatus) is a species of legume known by the common name riverbar bird's-foot trefoil. It is native to western North America from British Columbia to California to Utah, where it grows in moist spots in a number of habitat types. It is an annual herb growing erect or spreading to about 40 cm in maximum length. It is lined with leaves each made up of a few alternately arranged oval leaflets 1 to 2 cm long, sometimes slightly hairy in texture. The inflorescence is made up of one or two whitish to yellowish pealike flowers located in leaf axils. The fruit is a hairy legume pod up to about 1.5 cm long.