PEA FAMILY 



307 



32. T. dubium Sibth. Shamrock. Steins slender, 1 to many from base, erect 

 or ascending, ^ to II/2 feet long, pubescent above; leaflets obovate or cuneate, 

 denticulate, often emarginate, glabrous, 3 to 4 lines long, on very short petioles; 

 heads small (3 lines broad), the rachis elongated; flowers very small, in age re- 

 flexed; calyx 11/^ lines long, the teeth subulate, unequal, the longest about equaling 

 the tube; corolla yellow, turning brown, 1^^ to 2 lines long; pods 1-seeded. 



Naturalized from Europe, in streets, pastures and waste lands of valleys, 10 

 to 2000 feet: Del Norte Co.; Humboldt Co.; Nevada Co.; Calaveras Co.; San Fran- 

 cisco Bay region. Apr.-June. 



Locs. — Crescent City, Davy 5923; Areata, Davy 5602; Eureka, Chandler 1127; Scotia, Davy 

 5529; Holmes Flat, betw. South Fork and Scotia, Tracy 4699; Nevada City; Angels Camp, 

 Davy ; San Francisco, Agnes EricTcson; Berkeley, Blasdale. 



Eefs. — Trifolium dubium Sibth. Fl. Oxon. 231 (1794), type from Europe; McDer. N. Am. 

 Sp. Trifolium 306, pi. 129 (1910) ; Jepson, Man. 541 (1925). 



33. T. procumbens L. Hop Clover. Stems slender, decumbent or ascending, 

 6 to 13 inches long, finely appressed-pubescent, the leaflets glabrous; leaflets elliptic 

 or cuneate-obovate, often emarginate, 3 to 9 lines long, longer than the petioles; 

 heads globose or a little elongate, 4 to 5 lines long; flowers in age reflexed; calyx 

 about 1 line long, the teeth subulate, unequal; 

 corolla bright yellow, about 3 lines long, the 

 banner very broad; pods 1-seeded, stipitate. 



Naturalized from Europe, sparingly es- 

 tablished in roadways and lawns, 10 to 1500 

 feet : Humboldt Co. June. 



Locs. — Betw. Korbel and Angels ranch, Tracy 

 4523 in 1914 ; betw. Eureka and Areata, Jepson 1923 

 in 1902. 



Eefs. — Trifolium procumbens L. Sp. PI. 772 

 (1753), type from Europe; McDer. N. Am. Sp. Tri- 

 folium 306 (1910); Jepson, Man. 541 (1925). 



34. T. bifidum Gray, Pinole Clover. 

 (Fig. 200.) Stems erect, very slender, 

 branching, 7 to 17 inches high; stipules ovate- 

 lanceolate, setaceously acuminate, entire; 

 leaflets remarkably bifid, that is I/3 to ^ 

 their length, often with a prominent mucro 

 in the notch, the lobes coarsely toothed at 

 apex; leaflets of upper leaves 5 to 11 lines 

 long; peduncles pubescent at base of heads; 

 heads small, the flowers in age reflexed; calyx 

 pubescent; corolla purple or pale pink; ban- 

 ner characteristically patterned by the pecu- 

 liar venation. 



Open hills and valleys, 100 to 1500 feet : 

 coastal Southern California; Coast Ranges 



from Santa Clara Co. to Humboldt Co.; Sacramento Valley; Sierra Nevada foot- 

 hills from Mariposa Co. to Eldorado Co. May-June. 



Geog. note. — ^While widely distributed, Trifolium bifidum Gray is an infrequent species in 

 number of individuals as compared with several other annual species such as T. gracUentum 

 T. & G., T. fucatum Lindl., T. tridentatum Lindl. or T. microcephalum Pursh. We have no speci- 

 mens from the San Joaquin Valley; and occurrence in Southern California and the South Coast 

 Eanges is evidently rare. 



Locs. — Coastal S. Cal.: Morgan sta., sw. Los Angeles Co. (Proc. S. Cal. Acad. 1:7). Coast 

 Eanges: Los Gatos, Heller 7307; Woodside, San Mateo Co., C. F. BaTcer 743; Berkeley, Tracy 738; 

 Eutherf ord, Napa Valley, Chandler; Hopland, Mendocino Co., Tracy 5551 ; Trinity Eiver valley, 



Fig. 200. TRiFOLnjM bifidum Gray. 

 a, habit, X %; 6, A., X 5; c, calyx 

 spread open, X 5. 



