]^30 LEGUMINOS.E. Tri/uliiun. 



§ 4. Heads short, suhteuded bi/ an involucre, ivluch is usuallij many-cleft : leajlcts 3 : 

 pedanclts manifestly auillary: Jhwers mostly small, in whorls, sessile ur nearly 

 so, not rejiexed : annuals. 



* Involucre not membranaceous, deeply lobed, and the lobes laciniately and sharply 

 toothed: corolla not becoming mjlated. 



16. T. involucratum, Willd. Glabrous : stems ascending, often a span high 

 or more : stipules lanceolate to ovate, entire or usually lacerately toothed ; leailets 

 mostly oblaneeolate and acute at each end, a half to an inch long : involucre many- 

 cleft into narrow laciniate teeth : ilowers half an inch long, in close heads, purple 

 or rose-colored : calyx-teeth narrow, thin, gradually attenuate from the base, ex- 

 ceeding the tube, all entire : ovules mostly 5 or G. — T. Wormskioldii, J.ehm. Iiul. 

 Sem. llort. llamb. iH^f), 17. T. funbriatum, Lindl. ]}ot. J{eg. t. 1U70. 7'. spinu- 

 losum, Dougl. in Hook. Fl. i. 133. 



Var. heterodon, Watson. Heads mostly somewhat larger and leailets usually 

 broader: some of the calyx-teeth setaceously cleft. — Proc. Am. Acad. xi. 130. T. 

 heterodon, Torr. & Gray, Fl. i. 318. 



Of wide range, from the Britisli boumlary to Mexico, and from the coast to Colorado and New 

 Mexico ; and ([uite variable. Tlie variety, from Washington Territory to California. Though 

 the original species of Willdenow is of unci-rtain habitat and has been known only from culti- 

 vated specimens, yet there a])pears to be no snfiicient reason for distinguishing from it the better 

 known T.jiinbnatuin of Lindley. The Californian form is not distinct from the Mexican and New 

 Mexican plant ordinarily referred to T. involucratum, and Kunth's figure of Humboldt's Mex- 

 ican specimen, which was compared by lam with a garden specimen of Willdenow's species and 

 believed to dilfer only in its smaller size, represents fairly a low decumbent form of the present 

 species. 



17. T. tridentatum, Lindl. Glabrous or sometimes glandular-puberulent, 

 slender and usually erect, a half to two feet high : stipules ovate to lanceolate- 

 acuminate, laciniately toothed; leaflets linear to narrowly lanceolate, sharply serrate: 

 heads rather largo ; involucre many-cleft : Ilowers 6 to 8 lines long, in close heads, 

 purple, often tijjpcd with wliito : calyx strongly nerved ; the rigid teeth usually 

 shorter than the tube, broad at base and rather abrujjtly narrowed into the spinulose 

 apex, often with a stout tooth on each side : ovules usually two. — Bot. Keg. xiii, 

 under t. 1070. T. involucratum, Torr. & Gray, Fl. i. 318, not Willd. T. aciculare 

 & polyphyllxm, Ts^utt. in Torr. & Gray, 1. c. 



Var. obtlisifloi'um, Watsun, 1. c. Stouter and often glandular-puberulent, with 

 usually broader (dblong oblaneeolate) leailets and large heads of Ilowers : calyx-teeth 

 mih'e. — T.obtitsljlnrum, Honk. Ic. Tl. t. 281. 



Var. melananthum, Watson, 1. c Smooth, slemler, often low : heads snudler; 

 the dark purple Ilowers 4 or 5 lines long : calyx-teeth entire or toi)thtMl : leaflets 

 narrowly oblaneeolate or the lower obcordate. — 2\ melananthum, Hook. & Arn. 

 Bot. Beechey, 331. T. variegatum, var. /?., Torr. & Gray, Fl. i. 317 & GUI. 



A common and very variable species, from the British boundary to Southern California, mostly 

 confined to the Coast Hangcs ; the varieties froui Middle California, the latter ranging southward 

 and into Arizona, Palmer. Forms of this .species and of the last sometimes approach each other 

 so closely as not to be readily distinguished. 



18. T. pauciflorum, Nutt. Glabrous, very .slender: stems usually ascending 

 or decumbent : stipules ovate to lanceolate, laciniate ; leaflets obovate to oblaneeo- 

 late or sometimes linear, usually obtuse or retuse, half an inch long or less, serrulate: 

 heads rather few-flowered ; involucre small : flowers 3 or 4 lines long, not greatly 

 exceeding the calyx, deep purple or light rose-colored : calyx-teeth rigid, subulate 

 and setosely acuminate, exceeding the tube, entire : pod 2-seeded. — Torr. & Gray, 

 Fl. i. 319. 2\ varieyatum, Nutt. 1. c. T. oliganthum, Steudel. 



Common, usually in moist ground, from Washington Territory and Montana to Southern Cali- 

 fornia and Utah, both in the valleys and mountains ; Yosemite Valley {Bolander, Torrey, &c.) ; 

 Souora Pass, Brewer. 



