PEA FAMILY 531 



28. Trifolium amoenum Greene. Showy Indian Clover. Fig. 2683. 



Trifolium amoenum Greene, Fl. Fran. 27. 1891. 



Annual, more or less densely pubescent, the stems stout, erect, 1-6 dm. high, usually simple 

 below, and dichotomously branched above. Leaves nearly sessile; stipules with an elongated 

 subulate tip; leaflets broadly obovate, about 25 mm. long, entire or obscurely denticulate; pe- 

 duncles 3-10 cm. long, straight ; heads short-ovoid, 2-3 cm. long, dense ; calyx about 10-12 mm. 

 long, the teeth longer than the tube; corolla purple, tipped with white, 15 mm. long, exceeding 

 the calyx-teeth. 



Open grassy valleys and low hills, Upper Sonoran Zone; a rare species of the North Coast Ranges of Cali- 

 fornia, in Solano, Sonoma, and Marin Counties. Type locality: Vanden Station, Sacramento Valley, California. 

 April-June. 



29. Trifolium dichotomum Hook. & Arn. Branched Indian Clover. Fig. 2684. 



Trifolium dichotomum Hook. & Arn. Bot. Beechey 330. 1836-38. 

 Trifolium dichotomum var. turbinatum Jepson, Fl. W. Mid. Calif. 306. 1901. 

 Trifolium calif omicum Jepson ex McDermott, N. Amer. Trifol. 215. pi. 87. 1910. 



Annual, sparsely to densely pubescent, the stems erect or ascending; 15—4-0 cm. high. Leaves 

 slender-petioled ; stipules broadly lanceolate, abruptly acuminate ; leaflets 8-20 mm. long, cuneate- 

 obovate to elliptical; peduncles 5-15 cm. long, more or less recurved at apex; heads ovoid- 

 cylindrical, 12-25 mm. long; calyx 7-8 mm. long, the teeth twice as long as the tube; corolla 

 10 mm. long, exceeding the calyx-teeth, purple, tipped with creamy white; pods 1 -seeded. 



Usually in rocky or gravelly soils, Upper Sonoran Zone; California Coast Ranges from Humboldt County to 

 Santa Clara County. Type locality: "California." March-May. 



Trifolium petrophilum Heller, Muhlenbergia 2: 298. 1907. Closely related and probably not specifically 

 distinct from T. dichotomum, distinguished chiefly by the densely silky-pubescent leaves and stem and by the 

 densely villous calyx, the pubescence completely obscuring the ribs of the calyx-tube. Inner Coast Ranges of 

 central California. Type locality: Mount St. Helena, Napa County, California. March-May. 



30. Trifolium albopurpureum Torr. & Gray. Common Indian or Rancheria 



Clover. Fig. 2685. 



Trifolium albopurpureum Torr. & Gray, Fl. N. Amer. 1: 313. 1838. 

 Trifolium Macraei var. albopurpureum Greene, Fl. Fran. 26. 1891. 



Annual, villous-pubescent, the stems slender, ascending, or somewhat decumbent, 1-4 dm. 

 high. Stipules ovate-lanceolate, entire ; leaflets 1-2 cm. long, cuneate-oblong, obtuse, denticulate 

 above the middle; heads long-peduncled, ovoid, 8-15 mm. long; flowers sessile, not becoming 

 reflexed ; calyx villous ; corolla purple, 6-7 mm. long, scarcely equaling the calyx ; pod glabrous 

 or sparsely hairy at apex, 1-seeded. 



Open grassy hills and valleys, Upper Sonoran and Transition Zones; western British Columbia to southern 

 California. Type locality: California (Douglas). March-June. 



Trifolium albopurpureum var. neolagopus (Loja) McDermott, N. Amer. Trifol. 209. 1910. (Trifolium 

 neolagopus Loja, Nuov. Giorn. Bot. Ital. 15: 194. 1883.) More rigidly erect than the typical species, calyx 

 densely villous with long spreading hairs, the teeth three times as long as the tube; corolla 7-8 mm. long, equaling 

 or slightly exceeding the calyx-teeth, purple, often tipped with white; pod distinctly hairy at apex. Grassy plains 

 and foothills, Sacramento Valley and Sierra Nevada foothills to southern California. Type locality: near Chico, 

 California. 



31. Trifolium columbinum Greene. Dove Clover. Fig. 2686. 



Trifolium columbinum Greene, Pittonia 1: 4. 1887. 



Trifolium olivaceum var. columbinum Jepson, Man. Fl. PI. Calif. 546. 1925. 



Annual, the stem and leaves pubescent with upwardly appressed or ascending hairs, slender, 

 1-3 dm. high. Stipules lanceolate, acuminate, all but the uppermost leaves long-petioled ; heads 

 pedunculate, broadly conical, 15-20 mm. long; calyx densely plumose giving the head a dove 

 color, 8-9 mm. long, the tube scarcely over 1 mm. long ; corolla only half as long as the calyx, 

 and completely concealed by it ; ovary pubescent. 



Grassy hills, Upper Sonoran Zone; foothills of the northern Sierra Nevada and the North Coast Ranges, 

 California. Type locality: near Vacaville, California. March-May. 



32. Trifolium olivaceum Greene. Olive Clover. Fig. 2687. 



Trifolium olivaceum Greene, Pittonia 1 : 4. 1887. 



Annual, villous-pubescent and glaucous, the stems erect or ascending, 2-3 dm. high. Leaves 

 long-petioled ; stipules abruptly aristate, entire ; leaflets cuneate-obovate, 2-3 cm. long, serrulate ; 

 heads on short peduncles, broadly ovoid, 12-20 mm. long, bright olive-green; calyx with short 

 villous ascending hairs, about 8 mm. long ; corolla scarcely half the length of the calyx, purple 

 with paler tips ; pods glabrous, 1-seeded. 



Open grassy hillsides, Upper Sonoran Zone; North Coast Ranges and the Upper Sacramento Valley, Cali- 

 fornia. Type locality: near Vacaville, California. April-May. 



33. Trifolium cyathiferum Lindl. Bowl Clover. Fig. 2688. 



Trifolium cyathiferum Lindl. Bot. Reg. 13: under pi. 1070. 1827. 



Annual, glabrous, the stems erect or ascending, 1-3 dm. high. Stipules ovate to lanceolate, 



