Shivwits Milk Vetch

Tium eremiticum (Sheldon) Rydb. Bull. Torrey Club 40:49. 1913.
Astragalus eremilicus Sheldon, Minn. Bot. Stud. 1: 161. 1894.
Astragalus arrectus eremilicus M. E. Jones, Proc. Calif. Acad. II. 5: 665. 1895.
Astragalus eremilicus spencianus M. E. Jones, Contr. W. Bot. 10: 60. 1902.
Astragalus boiseanus A. Nelson, Bot. Gaz. 53: 223. 1912.
Cystium boiseanum Rydb. Bull. Torrey Club 40: 50. 1913.
Astragalus arrectus Kelseyi M. E. Jones, Rev. Astrag. 161, in part. 1923.
A cespitose perennial, with a woody root; stems several, 3-5 dm. high, sulcate, usually straw-colored or purplish, glabrous or nearly so; leaves 7-10 cm. long, ascending; stipules deltoid, 4-6 mm. long; leaflets 21-35, oblong to oval, 8-18 mm. long, 3-8 mm. wide, glabrous above, sparingly strigose beneath; peduncles 5-15 dm. long; racemes 5-10 cm. long, rather lax; bracts lanceolate, 2 mm. long; pedicels 1-2 mm. long; calyx sparingly black-hairy, the tube 5 mm. long, the teeth subulate, scarcely 2 mm. long; corolla white, ochroleucous, or purple, about 15 mm. long; banner obovate, notched at the apex; wings about 12 mm. long, the blade oblanceolate; keel-petals 10 mm. long, the blade broadly lunate, rounded at the apex; pod glabrous, the stipe about 1 cm. long, bent upward in fruit, the body oblong, rather abruptly contracted at each end, 1.5-2 cm. long, 5 mm. wide and 6 mm. thick, reniform in cross-section, the septum fully 1 mm. broad.
Type locality: Beaverdam Mountains, Utah.
Distribution: Arizona and southern Nevada to Idaho and Oregon.

Tium malheurense (A. Heller) Rydberg
Astragalus Cusickii Rydb. Bull. Torrey Club 26: 541. 1899. Not .4. Cusickii A. Grav. 1878. Astragalus malheurensis A. Heller. Cat. N. An. PI. ed. 2. 7. 1900.
A perennial; stems several, erect, 3-5 dm. high, strigose; leaves ascending, 6-10 cm. long, the rachis strigose; stipules lanceolate, 3 mm. long; leaflets 13-21, linear, 2-3 cm. long, about 2 mm. wide, acute, glabrous above, strigose beneath; peduncles 5-10 cm. long; racemes 5-10 cm. long, lax; bracts subulate, 2 mm. long; pedicels 1 mm. long; calyx black-hairy, 1.5 mm. long; corolla ochroleucous, with purple-tipped keel; banner 15-18 mm. long, obovate; wings 12-14 mm. long, the blade oblanceolate ; keel-petals 10 mm. long, the blade broadly lunate, rounded at the apex; pod glabrous, the stipe about 1 cm. long, curved upward, the body upright, oblong, 2 cm. long, the cross-section obcordate, the septum about 1 mm. wide.
Type locality: Malheur. Oregon. Distribution: Malheur County, Oregon.

Phaca cusickii (A. Gray) Rydb. Bull. Torrey Club 40: 47 1913.
Astragalus Cusickii A. Gray, Proc. Am. Acad. 13: 370. 1878.
Perennial, with a cespitose woody caudex; stems several, 3-4 dm. high, glabrous, angled and striate, leaves 5-10 cm. long, strongly ascending; stipules triangular, 2 mm. long and fully as broad; leaflets 11-17, nairowly linear, 6-20 mm. long, 0.5-1.5 mm. wide, sttigulose on both sides; peduncles 5-10 cm. long, glabrous; bracts ovate or lanceolate, 1 mm. long; calyxtube campanulate, 4 mm. long, sparingly stiigulose with black hairs, the lobes triangular, less than 1 mm. long; corolla ochroleucous, 12-15 cm. long; banner with an ovate obtuse blade and broad claw, slightly arched; wings shorter, the blade oblong, falcate, with a large rounded auricle; keel-petals much shorter, the blade broadly lunate; pod glabrous, the stipe about 3 mm. long, the body ellipsoid, 3-3.5 cm. long, 1-1.5 cm. wide; seeds obliquely reniform, 4 mm. long, 3 mm. broad, light-brown, smooth.
Type locality: Union County, Oregon.
Distribution: Eastern Oregon and Washington and western Idaho.

Astragalus ampullarioides is a rare species of milkvetch known by the common name Shivwits milkvetch. It was previously classified as a variety of Astragalus eremiticus. It is endemic to Washington County, Utah, where it is known from only seven populations. Estimates of the total number of individuals range from 1000 to 4200. The species occurs in desert scrub and woodlands on the Chinle Formation. It is a federally listed endangered species.

This is a perennial herb growing erect to a maximum height near half a meter. It produces about 45 flowers on an erect inflorescence. It is pollinated by bees.

Much of the plant's range is within the bounds of Zion National Park and Shivwits tribal lands. Other parts of the range are unprotected. Threats to the species include habitat loss to development and agriculture, herbivory by rabbits, cattle grazing, off-road vehicles, quarrying, and introduced plant species.