446 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



rated as of fair to good quality. L. wrightii and L. alamosanus are con- 

 sidered excellent for control of erosion. A decoction of the leaves and 

 flowers of L. rigidus is reported to have been used as a tonic by the 

 early settlers, under the name of Hills-tea. 



Key to the species 



1. Stipules membranous, subulate or narrowly lanceolate; plants perennial with 

 creeping rootstocks; umbels 1- to 5-flowered, on peduncles much surpass- 

 ing the leaves; corolla yellow; pods glabrous (2). 

 2. Stems stout, erect or nearly so; leaflets 7 to 11, narrowly lanceolate or elliptic 

 to obovate, 1 to 3 cm. long; corolla 10 to 14 mm. long, purple-veined; 

 pods about 2 mm. wide 1. L. oblongifolius. 



2. Stems slender, procumbent; leaflets 3 to 5, broadly obovate, less than 1 cm. 



long; corolla 5 to 7 (11?) mm. long; pods about 1 mm. wide. 



2. L. ALAMOSANUS. 



1. Stipules glandlike or obsolete (3). 



3. Corolla whitish, often fading pink; leaves mostly trifoliolate; calyx teeth 



subulate, much longer than the tube; plant annual, more or less pubes- 

 cent; stems erect or ascending, branched 3. L. purshianus. 



3. Corolla yellow or orange; leaves (some or all of them) usually with more 



than 3 leaflets; calyx teeth not, or not much, longer than the tube (4). 



4. Plants annual, flowering in spring; corolla not more (usually less) than 



7 mm. long; stems decumbent to prostrate (5). 



5. Pods indehi scent, with a beak (persistent style) nearly as long as to 



longer than the slender body and strongly incurved toward the 



apex like a fishhook ; umbels nearly sessile 4. L. hamatus. 



5. Pods dehiscent, with a straight or moderately curved beak much shorter 

 than the body (6) . 

 6. Stems and leaves soft-villous, usually copiously so; pods oblong, 2.5 to 



4 mm. wide, villous with long hairs 5. L. humistratus. 



6. Stems and leaves strigose with short hairs, often glabrate; pods 



linear, not more and usually less than 2.5 mm. wide, short-strigose 



or glabrate (7) . 



7. Rachis of the leaves usually at least 1 mm. wide; pubescence not 



very closely appressed; leaflets thickish, slightly succulent, 



cuneate-oblanceolate to rather narrowly obovate, rounded or 



truncate and often emarginate at apex; calyx teeth shorter 



than the tube 6. L. tomentellus. 



7. Rachis of the leaves usually less than 1 mm. wide; pubescence 

 closely strigose, sparse, the plant often glabrate; leaflets very 

 thin, broadly obovate, rounded to acutish, and often mucron- 

 ulate at apex; calyx teeth equaling or longer than the tube. 



7. L. SALSUGINOSUS. 



4. Plants perennial; corolla not less than 8 mm. long (8). 



8. Stems rigid, erect or ascending, somewhat woody below, the internodes 

 commonly more than twice as long as the leaves; leaves 3- to 5- 

 foliolate, the rachis distinct in leaves with more than 3 leaflets; 

 leaflets mostly obtuse or truncate, sometimes emarginate; peduncles 

 much surpassing the leaves; corolla 15 to 25 mm. long; pods 



glabrate 8. L. rigidus. 



8. Stems not rigid, herbaceous above the caudex, the internodes usually 

 much less than twice as long as the leaves (9) . 

 9. Peduncles shorter than the leaves or obsolete; leaves appearing digi- 

 tate, the rachis usually obsolete; leaflets (at least those of the up- 

 per leaves) acute or acutish; corolla 10 to 15 mm. long; pods 



commonly strigose at maturity 9. L. wrightii. 



9. Peduncles much longer than the leaves; leaves pinnate, the rachis 

 usually distinct but often very short (10). 

 10. Stems, leaves, and pods copiously villous; stems decumbent or 

 nearly prostrate; leaflets broadly cuneate-obovate to narrowly 

 oblanceolate, rounded and apiculate to acute at apex, up to 15 

 but usually less than 10 mm. long, 2 to 6 mm. wide; calyx 

 teeth commonly shorter than the tube, villous; corolla 12 to 18 

 mm. long; pods 20 to 30 mm. long, 2.5 to 3.5 mm. wide. 



10. L. GREENEI. 



