310 LEOUMINOSAE 



obovate, ^4 to V^ inches long; peduncles straight, IV2 to 4I/2 inches long; heads 

 globose-ovate, densely-flowered, 1 to l^/^ inches long; calyx-tube about I14 lines 

 long, the teeth conspicuously plumose, linear-subulate to filiform, 3 to 5 lines long ; 

 corolla purplish, tipped with white. 



Vallej^ fields, 20 to 200 feet : Marin and Sonoma Cos. to Solano Co. May-June. 



Field note. — The stem, in a striking and usual form of the species, is simple below and once- 

 forked above. Such plants with their very large heads, larger than those of any other native an- 

 nual clover, are, in seasons of good rainfall, interesting objects to the botanist in the late vernal 

 fields, all the more in that the individuals are commonly solitary, spaced a few rods or a quarter 

 mile apart. In this respect it differs markedly from the gregarious T. dichotomum H. & A., 

 though so closely related genetically to that species. 



Locs. — Olenia, Marin Co., K. Brandcgee; Petaluma, Tracy 5548; Napa Jet., Michener ^ 

 Bioletti; Vacaville, Jepson 13,649. 



Eefs. — Trifolium amoenum Greene, Fl. Fr. 27 (1891), type loc. Vanden, Solano Co., Greene; 

 Jepson, Fl. W. Mid. Cal. 306 (1901), Man. 545 (1925). T. dichotovium McDer. N. Am. Sp. Tri- 

 folium 219 (1910) in part; Jepson, Fl. W. Mid. Cal. ed. 2, 227 (1911) in part; not T. dichotomum 

 H. & A. (1840). 



39. T. dichotonmm H. & A. Indian Clover. Stems erect or ascending, 6 

 to 16 inches high ; herbage sparsely to densely pubescent ; petioles slender ; leaflets 

 ovate to elliptical or cuneate-obovate, 4 to 11 lines long; stipules small, ovate- 

 acuminate ; peduncles curved or retro-curved at apex, 2 to 6 inches long ; heads 

 cylindric to ovate-cylindric, most commonly a little spike-like, truncate at top, 

 turbinate at base, 6 to 12 lines long; calyx-tube about 1 line long, the teeth subulate- 

 filiform, plumose, 2^/2 to 31/2 lines long ; corolla cream-tipped, longer than the calyx ; 

 pods 1-seeded. 



Low hills, 200 to 1000 feet : Coast Ranges from Santa Clara Co. to Contra Costa, 

 Solano and Humboldt Cos. Apr.-May. 



Distribution note. — Locally gregarious on the lowest foothills, Trifolium dichotomum is 

 almost always found as colonies on heavy adobe soil. These colonies are commonly a few yards 

 to a rod across and usually sharply defined. Indian Clover is rather uncommon on the whole but 

 is seldom seen as solitary individuals. In the North Coast Eanges individuals with reduced 

 heads are sometimes collected ; such forms simulate T. albopurpureum T. & G., but the heads are 

 narrowly oblong as compared with that species. 



Locs. — Los Gatos, Heller 7423; betw. Mission San Jose and Livermore, Heller 7316; Crystal 

 Springs Lake, San Mateo Co., Davy 1068; Caux's Cabin, w. of St. Helena, Hoods Peak Range, 

 Jepson 13,664; Conn Valley, Napa Range, Jepson 6243, 13,647; Howell Mt., Jepson 13,665; 

 summit Pope Valley grade e. of Calistoga, Jepson 13,663 ; Rowes sta., n. Mendocino Co., Chandler 

 1038 ; Ft. Seward, Humboldt Co., Tracy 4452. 



Var. turbinatum Jepson. Three to 6 inches high; heads narrowly or broadly turbinate, 

 sometimes broadly ovate, 4 to 8 lines high ; corollas longer than the calyces. — Mountain slopes, 

 500 to 3000 feet:' Santa Clara Co. to Marin Co. 



Locs. — Mt. Hamilton, Jepson 4225, 4192; Rock Spr., Mt. Tamalpais, Jepson 7565; Ross 

 Valley, Marin Co., Jepson 13,648. 



Refs. — Trifolium dichotomum H. & A. Bot. Beech. 330 (1840), type from Cal., Douglas; 

 Jepson, Fl. W. Mid. Cal. 306 (1901), Man. 545, fig. 535 (1925). T. macraei var. dichotomum 

 Brew.; Wats. Proc. Am. Acad. 11:129 (1876). T. calif ornicum Jepson; McDer. N. Am. Sp. Tri- 

 folium 215, pi. 87 (1910) ; Fl. W. Mid. Cal. ed. 2, 228 (1911). Var. turbinatum Jepson, Fl. W. 

 Mid. Cal. 306 (1901), type loc. Ross Valley, Marin Co., Jepson 13,648; Man. 545 (1925). T. call- 

 f ornicum f. turbinatum Jepson; McDer. I.e. 217, pi. 88; Fl. W. Mid. Cal. ed. 2, 228 (1911). T. 

 petrophilum Hel. Muhl. 2:298 (1907), type loc. Mt. St. Helena, C. F. BaJcer 2625. T. dichotomum 

 f. petrophilum McDer. I.e. 221; Jepson, Fl. W. Mid. Cal. ed. 2, 227 (1911) 



40. T. albopurpureum T. & G. Rancheria Clover. (Fig. 201.) Stems 

 slender, ascending or slightly decumbent, 8 to 16 inches high; herbage pubescent; 

 leaflets obovate to cuneate-oblong, obtuse, 3 to 7 (or 12) lines long; heads hemi- 

 spherical, or somewhat elongated, 4 to 7 lines long, the terminal ones on long pe- 

 duncles, the lateral on short peduncles; corolla dark purple, barely or not at all 

 longer than the plumose calyx-teeth; pods 1 or 2-seeded. 



