PEA FAMILY 533 



laciniately toothed; leaflets 10-25 mm. long, obovate to elliptic-oblong, obtuse or acute; involucre 

 broad, bowl-shaped, membranous, nerved and toothed; calyx-teeth 1-3 times trichotomously- 

 f orked, equaling the rose-colored corolla ; pod 2-seeded. 



Valleys and hillsides, Arid Transition Zone; British Columbia and Idaho to northern California. Type 

 locality : Columbia River. May-June. 



34. Trifolium barbigerum Torr. Bearded Clover. Fig. 2689. 



Trifolium barbigerum Torr. Pacif. R. Rep. 4: 79. 1856. 



Annual, pubescent to glabrate, the stems several, rather stout, procumbent or decumbent, 

 radiating from the base, 1-2 dm. long. Stipules broadly ovate, scarious, laciniate; leaflets 6-8 

 mm. long, deltoid or obcordate to ovate-oblong, setate-serrulate : peduncles slender, involucre as 

 broad as the head and almost enclosing it, shortly lobed and setaceously many-toothed; calyx- 

 tube short, membranous ; teeth setaceously awned, plumose, the lower one sometimes 2-3-parted 

 and equaling or exceeding the corolla ; corolla dark purple, about 5 mm. long. 



Open hillsides near the coast mainly Humid Transition Zone; Del Norte County to Monterey County, Cali- 

 fornia. Type locality: near San Francisco, California. April-June. 



35. Trifolium Grayi Lola. Gray's Clover. Fig. 2690. 



Trifolium barbigerum var. Andrewsii A. Gray, Proc. Amer. Acad. 7: 335. 1867. 

 Trifolium Grayi Loja, Nuov. Giorn. Bot. Ital. 15: 189. 1883. 

 Trifolium lilacinum Greene, Proc. Acad. Phila. 1895: 547. 1896. 

 Trifolium Andrewsii Heller, Muhlenbergia 1: 114. 1905. 



Annual, more or less pilose throughout, the stem branched at the base and ascending, some- 

 what fistulous, 2-4 dm. long. Stipules large, 15-20 mm. long, laciniate; leaflets narrowly obovate, 

 12-20 mm. long; peduncles elongated, 15-20 cm. long; heads 20-25 mm. broad; involucre shal- 

 lowly bowl-shaped, the lobes laciniate; calyx much shorter than the corolla, the upper tooth 

 3-parted; corolla 10-12 mm. long, deep purple and often white-tipped. 



Wet meadows near the coast, Mendocino County to Monterey County, California. Type locality: not desig- 

 nated. April-June. 



36. Trifolium microdon Hook. & Arn. Valparaiso Clover. Fig. 2691. 



Trifolium microdon Hook. & Arn. Bot. Misc. 3: 180. 1833. 



Annual, glabrous, the stems erect, 1-6 dm. high, the branches slender. Stipules ovate-lanceo- 

 late, abruptly acuminate, entire or few-toothed; leaflets broadly obcordate to oblanceolate, 1-2 

 cm. long ; involucre deeply campanulate, glabrous and scarious below, 5-15-lobed, the lobes 

 several-toothed, green ; heads 6-7 mm. broad ; calyx 4-5 mm. long, the teeth very short, triangular, 

 abruptly apiculate, scarious and ciliate on the margin; corolla exceeding the calyx; 5-6 mm. 

 long, pale rose or white ; pod 1-seeded. 



Open hillsides and valleys, in rich soils, Transition and Upper Sonoran Zones; British Columbia to San 

 Luis Obispo County, California; also Chile. Type locality: Valparaiso, Chile. March-June. 



Trifolium microdon var. pilosum Eastw. Proc. Calif. Acad. III. 1: 100. 1898. Distinguished from the 

 typical form by the more or less pilose peduncles and involucres. Apparently the common form from British 

 Columbia to northwestern California, and occurring sparingly along the coast to San Nicolas Island, southern 

 California, which is the type locality. 



37. Trifolium microcephalum Pursh. Small-headed Clover. Fig. 2692. 



Trifolium microcephalum Pursh, Fl. Amer. Sept. 2: 478. 1814. 



Annual, sparingly villous, the stems branched from the base, the branches ascending or 

 procumbent, 2-4 dm. long. Stipules ovate, acuminate ; leaflets 5-15 mm. long, obcordate or 

 cuneate-obovate, emarginate, serrate; involucral lobes 7-10, lanceolate, with scarious web-like 

 margins ; heads small, 5-10 mm. long ; calyx pubescent, 4 mm. long, the teeth subulate, about 

 equaling the tube ; corolla rose to white, 6 mm. long ; pod 1-2-seeded. 



Open grassy hillsides and valleys, Transition and Upper Sonoran Zones; British Columbia and Montana to 

 Lower California and Nevada. Type locality: Bitter Root River, Montana, near the mouth of the Lolo. April- 

 Aug. 



38. Trifolium monanthum A. Gray. Carpet Clover. Fig. 2693. 



Trifolium monanthum A. Gray, Proc. Amer. Acad. 6: 523. 1865. 



Dwarf cespitose perennial from a taproot, 2-10 cm. high, sparsely villous-pubescent through- 

 out. Stipules lanceolate, entire or nearly so; petioles filiform, elongated; leaflets cuneate-obovate, 

 2-8 mm. long, rounded to acutish at apex ; peduncles filiform ; involucre small, 2-4-parted, the 

 the lobes entire or toothed, 2-3 mm. long; flowers 1-3, 10-12 mm. long, cream-colored with 

 purple-tipped keel ; pod 1-3-seeded. 



Alpine meadows and stream banks, Boreal Zone; Sierra Nevada, California, and western Nevada. Type 

 locality: Soda Springs, Tuolumne River, altitude 8,700 feet, California. June-Aug. 



Trifolium monanthum var. parvum (Kellogg) McDermott, N. Amer. Trifol. 105. 1910. Distinguished by 

 its taller (10—30 cm.), less matted stems: leaves often 6-10 mm. long, obtuse; heads 3-6-flowered ; flowers 6-8 

 mm. long. Grassy slopes, mainly Arid Transition Zone; Sierra Nevada, California, and western Nevada. 



Trifolium monanthum var. tenerum (Eastw.) Parish, Bot. Gaz. 38: 461. 1904. In habit much like the 

 preceding variety, but more villous; leaflets oblanceolate, acute, setose-serrate; involucre divided to the base, 

 flowers 1-6. 10-12 mm. long. Mountain meadows. Arid Transition and Canadian Zones; southern Sierra Nevada 

 to the San Jacinto Mountains, southern California. 



