516 FABACEAE 



35. KENTROPHYTA Nutt. 



Perennial, diffusely branched herbs. Leaves pinnately 3-7-f olio late; leaflets 

 linear or subulate, inarticulate, rigid, spinulose-tipped ; stipules more or less 

 united. Flowers small, 2 or 3 together in the axils. Calyx campanulate, deeply 

 5-cleft; teeth equal, subulate. Corolla ochroleucous or purplish; banner oblong, 

 reflexed; keel obtuse, shorter than the wings. Legume ovate, one-celled, flat, 

 with both sutures prominent, 1- or 2-seeded. 



Stipules united only at the base, more or less herbaceous. 



Plant 3-4 dm. high, usually erect; stipules lanceolate, with long spinulose tips. 



1. K. impensa. 



Plant low; stipules lance-subulate, not spinulose-tipped. 2. K. viridis. 



Stipules united for about half their length, scarious. 



Leaflets linear-filiform, scarcely narrowed at the base; corolla ochroleucous, sub- 

 sessile in the axils of the leaves. 3. K, montana. 

 Leaflets lanceolate or oblanceolate, distinctly narrowed at the base. 



Corolla ochroleucous, about 4 mm. long, the keel usually purple-tipped; leaflets 



less than 5 mm. long. 

 Flower-clusters subsessile or short-peduncled ; calyx-lobes shorter than the 



tube. 



Leaves short-hairy; stipules with long spreading tips; leaflets about 3 mm. 



long. 4. K. minima. 



Leaflets long-hairy; stipules not with spreading tips; leaflets 4-5 mm. long. 



5. K. Wolfii. 



Flower-clusters on peduncles much exceeding the leaves ; calyx-lobes equalling 



or exceeding the tube. 6. K. tegetaria. 



Corolla purple, about 6 mm. long; leaflets over 5 mm. long. 7. K. aculeata. 



1. K. impensa (Sheld.) Rydb. Stems erect or ascending, 3-4 dm. high, 

 simple or with short branches; leaflets 5-7, subulate or linear-lanceolate, 8-15 

 mm. long, strigose, strongly ribbed and pungent; calyx-tube 1.5 mm. long; teeth 

 1 mm. long; corolla ochroleucous, 4 mm. long. Astragalus Kentrophyta elatus S. 

 Wats. A. viridis impensus Sheld. Dry valleys: Nev. w Colo. Ariz. Son. 

 Submont. My-S. 



2. K. viridis Nutt. Stems diffusely spreading and much branched, 1-3 dm. 

 long; leaflets usually 5, subulate, pungent, 8-18 mm. long; calyx-tube 1.5-2 mm. 

 long; teeth 1.5 mm. long; corolla ochroleucous, 5 mm. long. A. Kentrophyta 

 A. Gray, in part. Plains, bad-lands, and hills: Wyo. Colo. Plain Submont. 

 My-Je. 



3. K. montana Nutt. Stems diffusely spreading, and intricately branched; 

 stipules ovate, 1-3 mm. long; leaflets 5-7, subulate, pungent, 8-15 mm. long; 

 calyx-tube 1.5-2 mm. long; teeth 1 mm. long; corolla ochroleucous, 4-5 mm. 

 long. A. Kentrophyta A. Gray, in part. Bad lands, canons, and sandy hills: 

 Sask. Neb. Utah Alta. Plain Submont. Je-Au. 



4. K. minima Rydb. Perennial forming cushions 1 dm. in diameter; 

 stems 1-2 cm. high; stipules lanceolate, 1-3 mm. long; leaflets 5-9, linear-lance- 

 olate, conduplicate, pungent, 3-4 mm. long; flowers usually solitary; calyx-tube 

 1-1.5 mm. long; teeth scarcely 1 mm. long; corolla about 3 mm. long. Moun- 

 tains: Yellowstone Park, Wyo. Mont. Au. 



6. K. Wolfii Rydb. Stems intricately branched, less than 1 dm. long; stipules 

 triangular; leaflets 5, approximate, 3-4 mm. long, lanceolate, strongly condupli- 

 cate; calyx-tube scarcely 2 mm. long; teeth about 1 mm. long; corolla about 4 

 mm. long. High mountains: Colo. Mont. Subalp. Jl. 



6. K. tegetaria (S. Wats.) Rydb. Stems diffuse-procumbent, 5-15 cm. 

 long, much branched; stipules lanceolate, acuminate, 3-5 mm. long; leaflets 7-11, 

 narrowly linear-lanceolate, pungent, 4^6 mm. long; calyx-tube scarcely 1.5 mm. 

 long; teeth fully 1.5 mm. long; corolla 4-5 mm. long. A. tegetarius S. Wats. 

 Mountains: Nev. (? Utah). Mont. Jl. 



7. K. aculeata (A. Nels.) Rydb. Stems less than 1 dm. long, diffusely 

 spreading or decumbent; stipules ovate, 4-5 mm. long; leaflets 5-9, narrowly 

 linear-lanceolate, conduplicate, 4-8 mm. long; calyx-tube about 1.5 mm. long; 

 teeth subulate, 1 mm. long; corolla 5-6 mm. long. A. aculeatus A. Neis. A. 

 tegetarius implexus Canby. High mountains : Mont. Colo. Utah Ida. Sub- 

 mont. Mont. Jl-Au. 



