PEA FAMILY 291 



folium Nutt. Jour. Acad. Phila. n. ser. 1:152 (1847), type loc. "near St. Simeon, Upper Cali- 

 fornia", Gamhel. T. depauperatum var. diver sifolium McDer. I.e. 135 ; Jepson, Fl. W. Mid. Cal. 

 ed. 2, 223 (1911). T. hydrophilum Greene, Man. Eeg. S. F. Bay 100 (1894), cent, "seaboard" of 

 California. T. amplectens var. hydrophilum Jepson, Fl. W. Mid. Cal. 311 (1901). Var. trxjn- 

 CATUM Jepson, Man. 537 (1925). T. franciscanum var. truncatum Greene, Man. Reg. S. F. Bay 

 100 (1894), type loc. Napa and Solano Cos. T. truncatum Greene, Proe. Acad. Phila. 47: 546 

 (1896). T. depauperatum var. amplectens f. truncatum McDer. I.e. 144; Jepson, Fl. W. Mid. 

 Cal. ed. 2, 224 (1911). 



3. T. depauperatum Desv. Alkali Clover. Stems slender, ascending, 4 to 

 8 inches high; herbage glabrous; leaflets euneate-emarginate, denticulate, 3 to 5 

 lines long; peduncles slender, wiry; heads loose, 2 to 7-flowered, 5 to 10 lines long; 

 involucre an exceedingly small or reduced ring; calyx-teeth triangular-subulate, 

 shorter or longer than the tube ; corolla whitish to purple, becoming inflated, the 

 banner enclosing the small wings and keel; pods stipitate, 2 to 6-ovuled, commonly 

 2-seeded. 



Alkaline valleys, or flats in the liills, 25 to 2500 feet: Coast Ranges from 

 Alameda Co. to Humboldt Co. ; Sacramento Valley. North to Oregon. Chile. 

 Mar.-May. 



Locs. — Coast Ranges: Alameda, Jepson 13,736; Byron Sprs., Contra Costa Co.; Mt. George, 

 Napa Range, Jepson 13,738 ; St. Helena, Jepson 13,739 ; Sherwood Valley, Mendocino Co., Davy 

 5192; Kneeland Prairie, Humboldt Co., Tracy 5480. Sacramento Valley: Peaceful Glen, nw. 

 Solano Co., Jepson 9613 ; Oroville, Keller 10,732 ; Anderson, Shasta Co., Alice King. 



The following leaf forms are rather marked. Var. laciniatum Jepson. Leaflets laciniately 

 toothed or lobed. — Eastern Contra Costa Co. Var. angustatum Jepson. Leaflets narrowly 

 linear, entire or dentate, 5 to 6 lines long. — Lone Willows sta., Fresno Co., Jepson 13,735; 

 Sonoma Valley, Brewer 980 ; Calistoga, Jepson 13,737. 



Refs. — Trifolium depauperatum Desv. Jour. Bot. 4:69, t. 32 (1814), type loc. "western 

 coasts of both North and South America"; Jepson, Fl. W. Mid. Cal. 311 (1901), ed. 2, 223 (1911), 

 Man. 537, fig. 525 (1925) ; McDer. N. Am. Sp. Trifolium 131, pi. 47 (1910). Var. laciniatum 

 Jepson, Fl. W. Mid. Cal. 311 (1901), Man. 538 (1925). T. laciniatum Greene, Pitt. 1:7 (1887), 

 type loc. Byron Sprs., Contra Costa Co., Greene. T. depauperatum f. laciniatum McDer. I.e. 133, 

 pi. 48; Jepson, Fl. W. Mid. Cal. ed. 2, 223 (1911). Var. angustatum Jepson, Man. 538 (1925). 

 T. laciniatum Greene var. angustatum Greene, Man. Reg. S. B. Bav 101 (L894), type loc. Byron 

 Sprs., Greene; Jepson, Fl. W. Mid. Cal. 311 (1901). 



4. T. tridentatum Lindl. Tomcat Clover. Stems several from the base, erect 

 or ascending, 4 to 20 inches high; leaflets linear-oblong to lanceolate, serrate-setate 

 to entire, % to 1% inches long; stipules laciniate-toothed, erect; heads hemispher- 

 ical, broader than long, % to 1% inches broad, the flowers standing out conspicu- 

 ously, the wings protruding at right angles from the tube-like fold of the banner; 

 involucre more or less deeply cleft into narrow lanceolate lobes; flowers 6 to 7 lines 

 long; calyx-teeth shorter than the calyx-tube, spine-tipped, dilated below, the 

 dilated portion sometimes raised into a shoulder or a very short sharp tooth on 

 each side; corolla bright to light purple, often white-tipped; pods mostly 2-seeded. 



Valleys, plains, hillslopes and canons, 50 to 4600 feet : coastal Southern Cali- 

 fornia; Coast Ranges; Great Valley. North to British Columbia. Mar.- June. 



Variation. — Trifolium tridentatum Lindl. is one of the most abundant and widespread 

 clovers of the valleys and lower foothills west of the Sierran crests, often dominating acres and 

 acres, especially in April and May. It has a fairly distinctive habit. The heads eome into 

 anthesis tnequilaterally and the corollas assume in their parts a characteristic pose. The field 

 student does not mistake it for any other species, because its organs are sufficiently uniform 

 within certain allowable limits of variation. Notwithstanding the considerable number of 

 synonyms here listed, it is not an especially variable species. Variability is most marked in the 

 calyx. The calyx-teeth, dilated below, may end in a long spine (var. aciculare McDer.) ; the 

 dilation may be more or less raised into a shoulder on one or both sides ; one or both the shoulders 

 may be more or less tooth-like, in rare cases subulate or ending in a very short spine (var. segetum 

 McDer.). Greene's Trifolium segetum was based on such a plant as a spm. from Alameda 

 (Tidestrom, May 16, 1895) in which the lateral teeth are short-acicular and unusually long 

 (1/4 to % line). The fallacy of species based on such features is shown by a remarkable sheet 

 (illustrating T. segetum) collected at Tracy by Benj. Cobb, consisting of two branchlets essen- 

 tially identical, save that in one the calyx-teeth are, most of them, similar to those of the Alameda 



