PEA FAMILY 



537 



50. Trifolium flavulum Greene. Yellow Sour Clover. Fig. 2705. 



Trifolium flavulum Greene, Pittonia 2: 223. 1892. 

 Trifolium virescens Greene, Pittonia 2: 223. 1892. 

 Trifolium fucatum var. flavulum Jepson, Fl. W. Mid. Calif. 310. 190'1. 



Pale green and glaucescent, the branches stout, prostrate, often 5-6 dm. long. Leaflets broadly 

 obovate, 15-20 mm. long, finely denticulate or entire; heads 5-15-flowered; calyx-teeth subulate, 

 the lower much exceeding the tube, corolla 10-15 mm. long, yellow tinged with purple or green. 



Moist, heavy soil, Upper Sonoran and Transition Zones; Vancouver Island to southern California. Type 

 locality: western California. April-June. The greenish-flowered form (7\ virescens) is an upland plant with 

 mostly ascending branches and smaller heads. 



51. Trifolium fucatum Lindl. Sour Clover. Fig. 2706. 



Trifolium fucatum Lindl. Bot. Reg. 22: pi. 1883. 1836. 



Trifolium physopetalum Fisch. & Mey. Ind. Sem. Hort. Petrop. 3: 47. 1837. 



Annual, glabrous, the stems stout, fistulous, diffuse, 2-8 dm. long. Stipules ovate, 15-20 mm. 

 long, entire; leaflets broadly obovate, 10-30 mm. long, coarsely denticulate; peduncles stout, 

 3-15 cm. long; involucral lobes lanceolate, acuminate. 12-18 mm. long; heads large, 2.5-4 cm. 

 in diameter; calyx scarious, the teeth shorter than the tube; corolla 20-25 mm. long, cream- 

 colored, the keel dark purple ; pod 3-8-seeded, stipitate. 



Moist places, Transition and Upper Sonoran Zones; northern California in the Coast Ranges, the Great 

 Valley, and the Sierra Nevada foothills to southern California. Type locality: California. April-June. 



52. Trifolium amplectens Torr. & Gray. Pale Sack Clover. Fig. 2707. 



Trifolium amplectens Torr. & Gray, Fl. N. Amer. 1: 319. 1838. 



Trifolium depaupcratum var. amplectens McDermott, N. Amer. Trifol. 142. 1910. 



Trifolium truncatum Greene, Proc. Acad. Phila. 1895: 546. 1896. 



Annual, light green, the branches slender, decumbent, 10-25 cm. long. Stipules entire ; leaf- 

 lets cuneate-obovate or oblong, 1-2 cm. long, rounded to retuse, serrulate; involucral lobes 3-4 

 mm. long, and about as broad, scarious-margined, entire or with one or two teeth ; calyx-tube 

 very short, the upper teeth short, the lower exceeding the tube ; corolla 6 mm. long, ochroleucous, 

 the standard much inflated in age ; pod 4-6-seeded. 



Grassy hillsides and valleys, Upper Sonoran Zone; chiefly in the Coast Ranges of central California. Type 

 locality: California. April-June. 



53. Trifolium stenophyllum Null. Narrow-leaved Sack Clover. Fig. 2708. 



Trifolium stenophyllum Nutt. Journ. Acad. Phila. II. 1: 151. 1848. 



Trifolium diversifolium Nutt. op. cit. 152. 



Trifolium franciscanum Greene, Man. Bay Reg. 100. 1894. 



Trifolium anodon Greene, Pittonia 5: 107. 1903. 



Trifolium brachyodon Greene, Pittonia 5: 107. 1903. 



Trifolium amplectens var. stenophyllum Jepson, Man. Fl. PI. Calif. 537. 1925. 



Annual, glabrous, the branches decumbent or ascending, 1-2 dm. long. Stipules entire; leaf- 

 lets 1-2 cm. long, narrowly cuneate-oblong to linear, acute to truncate and retuse at apex, den- 

 ticulate; peduncles very slender, well exceeding the leaves; involucral bracts green, or with a 

 narrow scarious margin, oblong, entire, 2-4 mm. long; calyx-tube very short, the upper teeth 



2699 

 2699. Trifolium melananthum 



2700 

 2700. Trifolium polyodon 



2701 

 2701. Trifolium variegatum 



