Preuss' Milkvetch

Phaca preussii (A. Gray) Rydb. Bull. Torrey Club 40:47. 1913.
Astragalus Preussii A. Gray, Proc. Am. Acad. 6: 222. 1864 Tragacantha Preussii Kuntze. Rev. Gen. 947. 1891. Rydbergiella Preussii Rydb. Fl. Rocky Mts. 501. 1917.
Perennial, with a woody taproot and a short cespitose caudex; stems several, 2-5 dm. high, sulcate, glabrous, stout; leaves 7-11 cm. long, spreading; stipules large, free, broadly deltoid, 5-7 cm. long; leaflets 11-15, oblong to broadly obovate, 8-18 mm. long, glabrous, obtuse to emarginate at the apex, somewhat fleshy; peduncles ascending, 5-10 cm. long, sulcate, glabrous; racemes 4—6 cm. long; bracts lanceolate, about 2 mm. long, equaling the pedicels; flowers spreading; calyx glabrous, cylindric, the tube about 7-8 mm. long, the teeth subulate, 2-2.5 mm. long; corolla purple, about 2 cm. long; banner obovate, slightly arched, emarginate at the apex; wings much shorter, the blade oblong, shorter than the claw, with a large reflexed auricle; keel-petals about as long and similar, slightly broader and more lunate; pod glabrous, stipitate, the stipe 5-8 mm. long, the body oblong-ellipsoid, 2-3 cm. long, about 1 cm. wide and thick; seeds obliquely reniform, 4 mm. long, 2.5 mm. broad.
Type locality: Banks of Rio Virgin |Nevada|.
Distribution: Central Utah to southeastern California and central Arizona.

Jonesiella arcta (Sheldon) Rydberg
Astragalus Preussii lalus M. E. Jones, Zoe 4: 36. 1893. Astragalus Preussii arctus Sheldon, Minn. Bot. Stud. I: 130. 1894. Rydbergiella arcta Rydb. Fl. Rocky Mts. 501, 1063. 1917.
A perennial, with a woody root; stems several, 3-5 dm. high, branched, striate or sulcate, glabrous; leaves ascending, 5-15 cm. long, the rachis glabrous; stipules deltoid, 4 mm. long; leaflets 15-25, elliptic, oblong, or oblanceolate, 8-20 mm. long, 3-5 mm. wide, glabrous; peduncles 8-15 cm. long, erect; racemes 2-4 cm. long; bracts lanceolate, 2-3 mm. long; pedicels 2-4 mm. long; calyx sparingly strigose, the tube 5 mm. long, the teeth subulate, 2-3 mm. long; corolla white, similar to that of /. Pattersoni; pod distinctly stipitate, the stipe 5-6 mm. long, exceeding the calyx-tube, the body oblong-ellipsoid, acute at each end, 1.5-2 cm. long, 6 mm. wide, cross-reticulate, glabrous, the septum about 2 mm. wide.
Type locality: Green River. Utah.
Distribution: Western Colorado, southeastern Utah, and northeastern Arizona.

Perennial, Herbs, Stems woody below, or from woody crown or caudex, Taproot present, Nodules present, Stems erect or ascending, Stems less than 1 m tall, Stems solid, Stems or young twigs glabrous or sparsely glabrate, Leaves alternate, Leaves petiolat e, Stipules conspicuous, Stipules membranous or chartaceous, Stipules persistent, Stipules free, 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 hairy, Petals separate, Corolla papilionaceous, Petals clawed, Petals pinkish to rose, Petals blue, lavander to purple, or violet, 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 freely dehiscent, Fruit oblong or ellipsoidal, Fruit or valves persistent on stem, Fruit fleshy, Fruit coriaceous or beco ming woody, Fruit exserted from calyx, Fruit beaked, Fruit glabrous or glabrate, Fruit 11-many seeded, Seeds cordiform, mit-shaped, notched at one end, Seed surface smooth, Seeds olive, brown, or black.

Astragalus preussii (common name - Preuss’ milkvetch) is an annual or perennial plant in the legume family (Fabaceae) found in the Colorado Plateau and Canyonlands region of the southwestern United States.: 121