trifoli i-M. LEGUMINOSJE. 137 



long, 2-seeded, dehiscent. Common on rocky hillsides and river banks, 

 Brit. Columbia to California. 



T. oligauthum Stead. Nom. i, 707. T. pauciflorum Nutt. not d'Ur- 

 ville. Glabrous annual: stems slender, erect, much branched from the 

 base and sometimes sparingly so above, about a foot high : stipules lacini- 

 ate, acuminate : lower leaflets on long petioles, cuneate-oblong, obtuse or 

 ^marginate, upper ones on short petioles, lanceolate-linear, acuminate, 

 8-10 lines long by 1 -2 lines broad, distinctly and minutely spinulose-ser- 

 rulate ; involucre 12-16-parted, about one-third the length of the flowers : 

 heads 5-7-fiowered, on long filiform peduncles ; teeth of the calyx simple, 

 broadly subulate, pungent, scarcely longer than the tube, shorter than the 

 petals; lower part of the corolla dull purple, upper part whitish : pods 2- 

 seeded. Wet places on the higher plains of the Columbia and Willamette 

 valleys. 



T. variegatum Nutt. T. & G. Fl. i, 317. Glabrous winter annual ; stem- 

 weak and decumbent, 8-12 inches long, branching from the base and spar- 

 ingly above : upper stipules roundish, laciniately dentate with subulate- 

 cetaceous teeth : leaflets obovate to oblong or somewhat obcordate, minutely 

 spinulose-serrate, 3-6 lines long, peduncles filiform, longer than the leave- : 

 involucre open-campanulate or at length spreading, laciniately many-cleft, 

 shorter than the flowers ; heads about 6 lines in diameter; teeth of the 

 glabrous calyx equal, lanceolate-subulate with setaceous points, longer 

 than the tube, shorter than the corolla: petals purple with white tips: 

 pods small, 2-seeded. Common in wet places throughout the Willamette, 

 valley. 



* * Involucre membranaceous, at least at base, less deeply lobed. 

 the lobes entire or toothed : corolla not becoming inflated: annuals. 



T. iiiicroreplialmii Pursh Fl. 478. Villous with soft hairs: stems 

 slender, erect or decumbent, 6-20 inches long, diffusely branched from the 

 base: stipules lanceolate to ovate, acuminate, mostly entire : leaflets ob- 

 lanceolate to obcordate or obovate, denticulate: 4-6 lines long: heads 

 small, densely many-flowered; involucre about 9-lobed, the lobes acumi- 

 nate, 3-nerved, entire: calyx hairy, its subulate teeth scariously margined. 

 sometimes toothed at base, attenuate to a long spinulose point, equalling 

 the corolla : ovules 2 ; pods glabrous, 1-seeded. Common in open places. 

 Brit. Columbia to California. 



T. microdon H. &. A. Bot. Beech, 330, t. 79. homewhat villous: 

 stems slender, erect or ascending, diffusely branched below, 6-12 inches 

 high: stipules lanceolate to ovate, spinulose-acuminate, entire; leaflets 

 obcordate, serrate, 4-8 lines long, nearly as broad: heads small, long- 

 peduncled ; involucre conspicuously cup-shaped, as long as the flower-. 

 9-12dobed, the oblong lobes laciniately toothed: calyx glabrous, eampanu- 

 late, 10-nerved, the short teeth triangular-subulate, spinose ; petals rose- 

 color: pods small, 1-seeded. On dry hillsides. Brit. Columbia to Cal- 

 ifornia. 



T. eyathiferum Lindl, Bot. Reg. under t. 1070. Glabrous: stems erect 

 or ascending. 4-12 inches high, diffusely branched: stipules ovate to 

 lanceolate, laciniately toothed or entire; leaflets obovate to oblanceolate. 

 obtuse or acute, 6-12 lines long by half as broad; heads 6-10 lines in 

 diameter, long-peduncled ; involucre broad and membranaceous, conspic- 

 uously nerved and reticulated, 7-10-lobed, the shallow acute lobes spinuloses 

 dentate, nearly as long as the flowers: calyx smooth, the tube somewhat 

 inflated, prominently 5-nerved, the nerves excurrent into branching seta- 

 ceous tips which equal the small white corolla: pods oblong, 2-seeded. 

 About springs and on wet rocks, Brit. Columbia to California and the 

 Rocky Mountains. 



* * * Involucre membranaceous: the upper petal becoming con \ 

 Spicuously inflated and enclosing the lower ones. 



