Basalt Milkvetch

Homalobus macgregorii Rydb. Bull. Torrey Club 50; 270. 1923.
A perennial, with a cespitose caudex; stems strigose, striate; leaves 5-8 cm. long; lower stipules triangular, scarious, connate, the upper ones more herbaceous, distinct; leaflets 13-19, linear, 10-15 mm. long, 1-2 mm. wide, strigose on both sides; peduncles 1-2 dm. long; racemes lax, 5-12 cm. long; bracts subulate, 2-3 mm. long; calyx strigose, the tube 4—5 mm. long, the teeth triangular, 1 mm. long or less ; corolla ochroleucous or white ; banner 1 2 mm. long, obovate ; wings 11 mm. long, the blade obliquely oblanceolate, equaling the claw; keel-petals 10 mm. long, rounded at the apex, the blade broadly lunate, with a rounded basal auricle; pod stipitate, the stipe 12-15 mm. long, slightly pubescent, the body glabrous, linear-elliptic, acute at each end, 2.5 cm. long, 5-6 mm. broad.
Type locality: Near Frazier Borax Mine, Mount Pinos, Ventura County, California. Distribution: Southern California and northern Lower California.

Homalobus stenophyllus (T. & G.) Rydb. Mem. N. Y. Bot Gard. 1: 249. 1900.
Astragalus leptophyllus Nutt. Jour. Acad. Phila. 7: 18. 1834. Not A. leplophyUus Desf. 1800.
Astragalus stenophyllus T. & G. Fl. N. Am. 1: 329. 1838.
Astragalus fili pes S. Wats. Bot. King's Expl. 75. 1871. Not H. filipes Torr. 1864.
Tragacantha stenophylla Kuntze, Rev. Gen. 948. 1891.
Phaca stenophylla Piper, Contr. U. S. Nat. Herb. 11: 371. 1906.
A perennial, with a cespitose woody caudex; stems erect, 3-10 dm. high, glabrous, striate and slightly angled; leaves 6-10 cm. long, erect or ascending; stipules lanceolate or deltoid, distinct or the lower connate; leaflets 9-15, linear, 1-2 cm. long, 1-2 mm. wide, glabrous on both sides or sparingly hairy beneath; peduncles 5-12 cm. long; racemes rather lax, 5-10 cm. long; bracts lanceolate, 1-2 mm. long; calyx black-strigose, the tube 3-4 mm. long, the teeth triangular, often obtuse, 1 mm. long or less; corolla yellow; banner obovate, 10-12 mm. long; wings 9-10 mm. long, the blade obliquely oblanceolate, acute or acutish, hastately auriculate at the base, about equaling the claw; keel-petals 8-9 mm. long, the blade broadly lunate, rounded at the apex and with a rounded basal auricle; pod stipitate, the stipe strigose, about 1 cm. long, the body linear-oblong, acute at each end, 2-2.5 cm. long, 4—5 mm. wide; seeds obliquely rcniform, 3-3.5 mm. long, 2-2.5 mm. broad.
Type locality: Headwaters of the Missouri.
Distribution: British Columbia to central Idaho, eastern Nevada, and California.

Homalobus filipes (Torr.) A. Heller, Muhlenbergia 9: 67. 1913
Astragalus filipes Torr. ; A. Gray, Proc. Am. Acad. 6: 226. 1864. Tragacantha filipes Kuntze, Rev. Gen. 944. 1891.
A perennial, with a cespitose caudex; stems erect, slender, branched, 3-10 dm. high, strigose; leaves 5-8 cm. long; stipules lanceolate to triangular, more or less adnate to the petioles but not connate; leaflets 7-1 1, linear to filiform, strigose, 8-15 mm. long, 1 mm. or less wide; racemes lax, including the peduncle 1-2 dm. long; bracts subulate, 1-2 mm. long; calyx strigose with mixed white and black hairs, the tube 3 mm. long, the teeth deltoid, 1 mm. long, acute; corolla white; banner 8 mm. long, obovate; wings nearly as long, the blade obliquely oblanceolate, with a rounded basal auricle, about equaling the claw; keel-petals lunate, with a rounded apex and a large rounded basal auricle; pod sparingly strigulose, the stipe 8-10 mm. long, the body oblong, about 2 cm. long, 4—5 mm. broad.
Typh locality: Interior of Washington, near Fort Okanogan. Distribution: Washington, Oregon, Idaho, and Nevada.

Perennial, Herbs, Stems woody below, or from woody crown or caudex, 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 glabrous or sparsely glabrate, Stems or young twigs sparsely to densely hairy, Leaves alternate, Leaves petiolate, Stipules conspicuous, Stipules membranous or chartaceous, Stipules persistent, Stipules connate to each other, forming a tuber or sheath, Leaves compound, Leaves odd pinnate, Leaf or leaflet margins entire, Leaflets opposite, Leaflets 10-many, Leaves hairy on one or both surfaces, Inflorescences racemes, Inflorescence axillary, Bracts very small, absent or caducous, Flowers zygomorphic, Calyx 5-lobed, Calyx glabrous, Petals separate, Corolla papilionaceous, Petals clawed, Petals white, Petals ochroleucous, cream colored, Petals greenish yellow, Petals orange or yellow, Banner petal narrow or oblanceolate, Wing petals narrow, oblanceolate to oblong, Wing tips obtuse or rounded, Keel petals auriculate, spurred, or gibbous, Keel tips obtuse or rounded, not beaked, Stamens 9-10, Stamens diadelphous, 9 united, 1 free, Filaments glabrous, Style terete, Style persistent in fruit, Fruit a legume, Fruit stipi tate, Fruit unilocular, Fruit freely dehiscent, Fruit elongate, straight, Fruit oblong or ellipsoidal, Fruit or valves persistent on stem, Fruit exserted from calyx, Fruit beaked, Fruit glabrous or glabrate, Fruit hairy, Fruit 11-many seeded, Seeds cordiform, mit-shaped, notched at one end, Seed surface smooth, Seeds olive, brown, or black.

Astragalus filipes is a species of milkvetch known by the common name basalt milkvetch. It is native to western North America from British Columbia to California to Utah, where it grows in many types of habitat, especially dry areas.