Trifolium. LEGUMINOSyE. 227 



Corolla becoming conspicuously inflated. 



More or less villous : involucre broad, setaceously many-toothed : 



calyx-teeth filiform, plumose. 23. T. BAiiniOERrM. 



Smooth, stout : flowers large : involucre broad, deeply lobed or parted ; 



lobes entire : teeth narrowly subulate. 24. T. FUCATr.M. 



Smooth, low and slender : flowers few, small : calyx-teeth narrowly 

 subulate. 

 Involucre with oblong entire obtuse lobes, equalling the calyx. 26. T. amplectens. 



Involucre nearly wanting, merely a toothed or entire disk. 25. T. uei'aui'euatum. 



§ 1. Heads not involucrate, dense: leaflets 5 to 7, rarely 3, thick : jioivers sessile: 

 cali/.r-tceth nearly eqxial, filiform, plumose: perennial. 



1. T. megacephalum, Nutt. Stout, a span high or less, somewliat villous : 

 stipules large, ovate-obloug, serrate ; leaflets cuneate-ohloiig to ohovate, obtuse, 

 mucronate, an inch long or less, toothed : heads mostly terminal, pedunculate, large : 

 flowers spicate, an inch long, purplish : calyx half as long, the teeth very much 

 longer than the tube: pod stipitate, 6-ovuled, smooth. — Gen. ii. 105; Torr. & 

 Gray, Fl. i. 315. Lnpinaster macrocephaliis, Pursh, Fl. ii. 479, t. 23. 



Sierra Valley, Sierra Co. {Lemvion) ; Diamond Mts., N. Nevada {Wheeler) ; northward in the 

 mountains to the British boundary {Lyall) : rather rare. 



2. T. Andersonii, Gray. Dwarf, cespitose, densely silky-villous, leafy : stip- 

 ules lanceolate, acuminate, entire ; leaflets cuneate-oblong, half an inch long, acute, 

 nearly entire : peduncles mostly axillary, shorter than the leaves : flowers half an 

 inch long, purplish, umbellate ; the outer bracts forming a rudimentary involucre : 

 calyx-teeth a little shorter than the petals : pod tomentose, about 5-ovuled, 1-2- 

 seeded. — Proc. Am. Acad. vi. 522. 



Sierra Valley (Lemmon) ; Carson Valley, Nevada, Anderson. Growing in dense tufts or mats, 

 3 or 4 inches high, the stout bases of the stems almost woody. " The roots grow very deep, and 

 so strong are the fibres that an ordinary breaking plough with two yokes of oxen can scarcely tear 

 them up." 



3. T. Lemmoni, AVatson. Dwarf, cespitose, alpine, sparingly appressed-pubes- 

 cent : stems rather slender, from a thick root : stipules ovate, acuminate, coarsely 

 toothed ; leaflets obovate, obtuse, coarsely toothed, lialf an inch long or less : pedun- 

 cles mostly terminal, equalling the leaves : heads small, the rhachis only two lines 

 long : flowers numerous, spicate, very small (so far as known) : calyx villous, two 

 lines long, exceeding the purplish petals : standard strongly hooded : ovary smooth, 

 2-ovuled. — Proc. Am. Acad. xi. 127. 



Lassen's Peak, Lemmmi. The few specimens are imperfect, only a few perhaps undeveloped 

 flowers remaining, upon the receptacle. 



§ 2. Heads not involucrate, terminal or apiparently so, peduncidate : leaflets 3 : flowers 

 sessile or nearly so : hiennial or j^erennial. 



* More or less pubescent : ccdyx-teeth very narrow, longer than the tube, 2dumose or 

 hairy: stipules lanceolate, acuminate. 



4. T. eriocephalum, Nutt. Erect, a span high or more, villous with spread- 

 ing hairs, or tlie stem and leaves rarely glabrous : stipules long, nearly entire ; leaf- 

 lets narrowly oblong or sometimes broader, 1 to H inches long, serrulate : flowers 

 in dense ovate spikes, at length reflexed, 4 to 6 lines long, ochroleucous : calyx- 

 teeth very villous, filiform, lax, nearly equalling the petals : ovary hairy, 2-4- 

 ovuled. — Torr. & Gray, Fl. i. 313. 



Mendocino Co. (Bolander), and frequent in Oregon and Idaho, on moist soils. 



5. T. plumosum, Dougl. Erect or ascending, a foot high or more, stout, some- 

 what appressed-villous : stipules long, entire or toothed ; leaflets narrowly oblong to 

 linear, 2 to 4 inches long, serrulate : flowers in dense oblong or ovate spikes, not 



