200 FABACEAE. 



Calyx-teeth half as long as the tube or less. 

 Leaves silvery-pubescent. 



Umbels sessile or short-peduncled. 3. S. argophyllum. 



Umbels on peduncles longer than the 



leaves. 4. 5. davidsoni. 



Leaves finely pubescent, but green and 



not at all silvery. 5. S. traskiae. 



Umbels bractless. 



Plants silvery-pubescent. 6. 5. sericeum. 



Plants not silvery. • ' 



Umbels sessile. 7. S. glahrum. 



Umbels pedunculate. 8. S. dendroideum. 



1. S. heermanni (D. & H.) Greene. Branches numerous, 

 flexuose, weak and prostrate, 3-10 dm. long; pubescence spreading 

 and slightly tomentose; leaflets 5-7, obovate or cuneate-oblong, 

 4-8 mm. long; umbels on short peduncles or sessile; flowers less than 

 5 mm. long; calyx half as long, somewhat villous; the teeth filiform, 

 about equaling the tube. 



Canyons of the San Gabriel and Santa Ana Mountains, below 

 4000 feet. 



2. S. ornithopum Greene. Perennial from a woody base; stems 

 3 dm. high, densely silky throughout, the branches many, rigid, 

 ascending; leaves 12-24 mm. long; leaflets 4-7, 7-12 mm. long, 

 oblong, acute at both ends; umbels numerous, on peduncles longer 

 than the leaves, single-bracted, many-flowered; flowers 8-9 mm. 

 long; calyx 4-5 mm. long, the teeth about equaling the tube, subu- 

 late; pod 2-3-seeded, long-rostrate, strongly curved upward. 



Mainly an insular species, found on Santa Barbara, San Nicholas, 

 Santa Catalina, San Clemente and Guadelupe Islands, also on the 

 mainland in Lower California. 



3. S. argophyllum (Gray) Greene. Densely silvery-silky through- 

 out; stems herbaceous, decumbent or ascending, 3-6 dm. long; 

 leaflets 3-7, obovate and rounded, or oblong and acute, 5-12 mm. 

 long; umbels dense, capitate, on short simple bracted peduncles; 

 flowers 8-10 mm. long; calyx half as long; the teeth filiform, nearly 

 as long as the tube, silky. 



In the pine belt of the San Gabriel and San Bernardino Moun- 

 tains. 



4. S. davidsoni Greene. Suffrutescent at the very base, the 

 slender branches 3-6 dm. long, prostrate or decumbent, only sparsely 

 leafy, floriferous chiefly near the ends; herbage canescent with an 

 appressed silky pubescence; leaflets 3-5, cuneate-obovate, obtuse 

 or acutish, 4-8 mm. long; umbel unifoliate-bracted, many-flowered, 

 on a slender peduncle, 2.5 cm. long or less, usually exceeding the 

 leaves; calyx-tube 2 mm. long; the teeth slender, 1 mm. long; corolla 

 about 6 mm. long, sulphur-yellow, becoming deep red in age; pod 

 strongly arcuate. 



Wilson's Peak, where it was first collected by Davidson. This 

 species is very close to S. argophyllum and may be only a form of 

 it. May-July. 



