Looseflower Milkvetch

Homalobus tenellus (Pursh) Britton; Britt. & Brown, 111. Fl. 2: 305. 1897.
Astragalus tenellus Pursh, Fl. Am. Sept. 2: 473. 1814. ■Ervum mullijlorum Pursh, Fl. Am. Sept. 2: 739. 1814. Homalobus multifiorus T. & G. Fl. N. Am. 1: 351. 1838.
Homalobus nigrescens Nutt.; T. & G. Fl. N. Am. 1: 351, in part, as rynonym. 1838. Astragalus nigrescens A. Gray, Am Jour. Sci. II. 33: 410. 1862. Astragalus multifiorus A. Gray, Proc. Am. Acad. 6: 226. 1864. Tragacantha tenella Kuntze, Rev. Gen. 942. 1891.
A perennial, with a cespitose caudex, closely resembling the preceding; stems 3-5 dm. high, sparingly strigose; stipules ovate to lanceolate, connate; leaves 5-10 cm. long; leaflets 13-21, linear or oblong, obtuse, 1-2 cm. long, 1-3 mm. wide, glabrous on both sides, or with scattered hairs beneath; racemes 4-8 cm. long, short-peduncled, many-flowered; flowers as in the preceding, but the corolla usually smaller, rarely more than 6 mm. long; pod glabrous, stipitate, the stipe 3-4 mm. long, the body 8-10 mm. long, 3 mm. wide, reticulate; seeds 3 mm. long, 1.5 mm. wide.
Tyte locality: Banks of the Missouri. Montana. Distribution: Manitoba to Yukon, Nevada, and Colorado.

Homalobus dispar Nutt.; T. & G. Fl. N. Am. 1: 350. 1838
. Orobus dispar Nutt. Gen. 2: 95. 1818.
Phaca nigrescens Hook. Fl. Bor. Am. 1: 143. 1831. • Physondra dispar Raf. Atl. Jour. 145. 1832.
Homalobus nigrescens Nutt.; T. & G. Fl. N. Am. 1: 351, in part, as synonym. 1838.
A perennial, with a cespitose rootstock or caudex; stems 2-5 dm. high, sparingly strigose or glabrate, striate; stipules ovate or deltoid, connate, the upper green, the lower scarious, soon blackening; leaves 4—6 cm. long, blackening in drying; leaflets 11—21, linear-oblong to oval, 8-15 mm. long, 2-6 mm. wide, obtuse or acute, glabrous above, with scattered hairs beneath; racemes many-flowered, lax, 4-8 cm. long, very short-peduncled; bracts subulate, 2 mm. long; calyx sparingly strigose, the tube 2 mm. long, the teeth lanceolate, 1 mm. long; corolla ochroleucous, the keel purple-tipped; banner 6-7 mm. long, obovate, retuse; wings 5-6 mm. long, the blade broadly obliquely oblanceolate, with a rounded basal auricle; keel-petals slightly shorter, with a rounded inflexed tip and a rounded basal auricle, the blade somewhat longer than the claw; pod short-stipitate, ellipsoid, acute at each end, about 1 cm. long and 4 mm. wide, glabrous, reticulate, the stipe shorter than the calyx; seeds black, oblong-reniform, 3 mm. long, 1.5 mm. broad.
Type locality: Hills near Fort Mandan. North Dakota.
Distribution: Saskatchewan and Alberta to Wyoming, Colorado, and western Nebraska.

Homalobus standleyi Rydb. Bull. Torrey Club 50: 182. 1923
Astragalus tenellus dementis F. Macbr. Contr. Gray Herb. 65: 35, in part. 1922.
A perennial, with a cespitose caudex; stems 2-3 dm. high, sparingly strigose; stipules deltoid, about 2 mm. long, connate; leaves 3-5 cm. long; leaflets 9-15, elliptic or oblong, 5-10 mm. long, 2-3 mm. wide, glabrous above, strigose beneath; racemes lax, including the short peduncle 4-7 cm. long; bracts lance-subulate, 1-2 mm. long; calyx strigose, the tube 2 mm. long, the teeth subulate, fully 1 mm. long; corolla white or tinged with purple, the keel purpletipped; banner 6 mm. long, obovate, slightly retuse; wings 5 mm. long; keel-petals 5 mm. long, with a rounded apex; pod about 1 cm. long, 3 mm. broad, strigose, elliptic-oblong, acute at each end, short-stipitate, the stipe shorter than the calyx-tube.
Type locality' : Ponchuelo Creek, New Mexico. Distribution: Known only from the type locality.

Homalobus strigulosus Rydb. Bull. Torrey Club 34: 420. 1907
Astragalus tenellus f. strigulosus F. Macbr. Contr. Gray Herb. 65: 34. 1922.
A perennial, with a cespitose caudex; stem erect or ascending, branched, 1-3 dm. high, strigulose; stipules ovate, short, blackening; leaves 3-4 cm. long; leaflets 11-17, linear, acute, 8-12 mm. long, 1-2 mm. wide, thick, glabrous above, strigose beneath; racemes lax, including the short peduncle 2-4 cm. long, 4— 7-flowered; bracts subulate, minute; calyx strigulose, the tube 1.5-2 mm. long, the teeth subulate, less than 1 mm. long; corolla ochroleucous, similar to that of the preceding; banner 6 mm. long; wings about 5 mm. long and keel-petals fully 5 mm. long; pod strigulose, shining, stipitate, the stipe about 3 mm. long, the body 1-10 mm. long, 3 mm. wide.
Type locality: East Humboldt Mountains, Nevada. Distribution: Utah and eastern Nevada.

Homalobus clementis Rydb. Bull. Torrey Club 31: 563. 1904
Astragalus tenellus Clementis F. Macbr. Contr. Gray Herb. 65: 35. 1922.
A perennial, with a cespitose caudex or rootstock; stems ascending or erect, 2-3 dm. high,
sparingly strigose or glabrate; stipules broadly triangular, acuminate, connate, about 3 mm.
long; leaves 5-8 cm. long; leaflets 11-21, oblong or lanceolate, acute, 7-12 mm. long, glabrous
above, sparingly strigose beneath; racemes 8-12-flowered, including the petiole 7-10 cm. long;
bracts lanceolate, 2 mm. long; calyx strigose with black hairs, the tube 2.5-3 mm. long, the
teeth about 1.5 mm. long; corolla purplish; banner 7-8 mm. long, obovate; wings 6-7 mm. long,
the blade obliquely oblanceolate; wing-petals 5—6 mm. long, with a rounded tip; pod oblong,
sessile, about 1 cm. long and 4 mm. wide, black-hairy, the upper suture almost straight; seeds
black, obliquely reniform, 2.5 mm. long, nearly 2 mm. broad.
Type locality: Sangre de Cristo, Colorado. Distribution: Colorado.

Perennial, Herbs, Stems woody below, or from woody crown or caudex, 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 sparsely to densely hairy, Leaves alternate, Leaves petiolate, Stipules conspic uous, Stipules green, triangulate to lanceolate or foliaceous, Stipules membranous or chartaceous, Stipules persistent, Stipules free, Stipules connate to each other, forming a tuber or sheath, Leaves compound, Leaves odd pinnate, Leaf or leaflet margins entire, Leaflets opposite, Leaflets alternate or subopposite, 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 hairy, Petals separate, Corolla papilionaceous, Petals clawed, Petals white, Petals ochroleucous, cream colored, Petals bicolored or with red, purple or yellow streaks or spots, 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 stipitate, Fruit unilocular, Fruit tardily or weakly 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 3-10 seeded, Seeds cordiform, mit-shaped, notched at one end, Seed surface smooth, Seeds olive, brown, or black.