10 RANUNCULACE-^i:. ThaJiclrum. 



tains to Moutaua ami Wvoining. Varial)le species, passing into the two followiug extreme 

 forms. 



Var. Wrightii, Trei.ease. Slender and small-leaved : all or most of the cauline 

 leaves conspicuously petioled ; leaflets from a quarter t<> over lialf inch long : akencs smaller, 

 usually few, more angulate-tumid, the midnerve being carinate-salicnt at maturity: seed 

 oval-<jblong, almost completely filling the cell. — Proc. Bost. Soc. Nat. Hist, xxiii. 304. T. 

 Wrightii, Gray, PI- Wriglu. ii. 7. — New Mexico and S. Arizona, a form of a drier district, 

 first coll. by \Vri(jht. (Adj. .Mex.) 



Var.* platycarpum, Tkelease, l. c. Inflorescence sparsely glandular-pnoerulent : 

 akenes large and flat, erect, 2 to .3 lines long and often fully 2 lines bruad, acuminate : vein.s 

 scarcely reticulated. — Coville, Coutr. U. S. Nat. Herb. iv. 55. T. hesperium, Greene, 

 Pittouia, ii. 24. — Foothills and high sierras of Centr. and S. California, Kelloijg & Harford, 

 Cnene, Gnu/, J\irisit Bros. 

 T.* polycarpmn, Watsox. Mostly robust and tall, thinner-leaved and glabrous through- 

 out : akene.s mure numerous, in fruit forming a globular head, larger (3 lines long including the 

 stii)e-like base, and two lines wide), flatter, but vesicular when fresh, obovate or somewhat 

 orbicular, only the midu^rve usually apparent and that with some branching veins, the cell 

 by no means filled by the oblong-linear seed. —Proc. Am. Acad. xiv. 288, & Bot. Calif, ii. 

 424. T. Feudleri, var. ? poli/carimm, Torr. Pacif. R. Ilep. iv. 61, mainly. T. Fendleri, 

 Brew. & Wats. Bot. Calif, i. 4, mainly. T. aexium, Greene, Fl. Francis. 309, a form with 

 leaves incised nearly as in the original specimens collected by Bigelow. — Shady grounds, 

 through California, especially along the coast, apparently to Montana. Seemingly the fruit 

 is a monstrous condition, but it matures seed. 

 T. occidentale, (tRay. a foot or two high, with 2 or 3 usually slender-petioled cauline 

 leaves : leaflets membranaceous, glaucescent, commonly an inch or more long, the lobes 

 rounded ; akenes rather few or few maturing, lanceolate or oblong-lanceolate and acuminate, 

 hardly at all oblicpie, 3 to 5 lines long, hardly over a line wide, prominently 3-norved on 

 each convex face, the midnerve slightlv more salient : seed nearly linear and filling the 

 cell. —Proc. Am. Acad. viii. 372; Wats. ibid. xiv. 28». T. dioicum, var. oxi/carpum, Torr. 

 Bot. Wilkes Exped. 212. — Moist and shaded ground, Brit. Columbia, east to Montana, and 

 south to Plumas Co.. California. T. megacarpum, Torr. in prem. Rep. 87 (name only) & 

 Trelease, 1. c. 303, is probably a form of this species with shorter broader akenes and some- 

 what thicker leaflets, thus forming a transition to some forms of T. Fendleri or perhaps the 

 following. 

 T.* venulosum, Trelease. Qnite smooth and very glaucous, 10 inches to 3 feet high : 

 stem and petioles often purplish and finely mottled : leaves 3-4-ternately divided, borne 

 upon rather long but stoutish and firm petioles ; primary divisions well stalked but leaflets 

 approximate, with .short petiolules, rather more firm of texture and smaller than in the 

 preceding species and veiny upon the pale or whitened lower surface, suborbicular in out- 

 line, crenately lol»ed : inflorescence commonly narrow: achenia 6 to 8, ovate, not strongly 

 flattened, almost sessile, narrowed to a slender straight or moderately curved beak, walls 

 thickish, at lea.st fii>mer tharn in the neighboring species; ribs forming at maturity prominent 

 free angles not connectedly reticulation. — Proc. Bost. Soc, Nat. Hist, xxiii. 302. ? T. Fend- 

 leri, J. M. Macoun, Bot. Gaz. xvi. 285. — Mountainous districts from Colorado, Parri/, 

 Va'sei/, and S. Dakota, R;idheig, to Oregon, Cusick; Washington, y^asei;, Piper, Hull, 

 Henderson, and Rocky Mts. of Brit. Columbia? Macoun. A species nearly related to the 

 eastern 7'. dioicum. A doubtful specimen with more expanded inflorescence has been 

 collected on the plains of the Saskatchewan, Bourgean. 



^_^_ Eastern species; akenes terete or nearly so, costateangled (some, of the ribs rarely 

 branching or anastomosing), little or not at all gibbous, either sessile or short-stipitate (in 

 the same species), thick-walled, the cell filled by the seed: filiform-subulate styles elon- 

 gated, surpassing the sepals. 

 ++ Mostly tall (2 to 8 feet high) : leaves 3 or 4 times ternate; cauline several, upper or all 

 of them se.ssile or subsessile by a spathaceous base ; leaflets from roundish to oblong, com- 

 monly with mucronate lobes or tip, of rather firm texture: akenes ovoid or short jblong. 

 seldom over 2 lines long, wnth 5 or 6 acute angulate ribs, the sutural ones slightly more 

 salient : .sepals caducous : filaments white in anthesis, or sometimes purplisli : styles 

 tardilv brcakins: awav 



