Crepis. composite. 489 



5. C. elegans (Hook.) : perennial, very glabrous and glaucous ; stems 

 numerous from the same fusiform root, slender, paniculate, bearing nume- 

 rous (small) 10-14-flowered heads ; radical leaves oval or spatulate, petioled, 

 nearly or quite entire ; the cauline narrowly spatulate ; the upper linear, ses- 

 sile. — Hook. ! ji. Bor.-Am. 1. p. 297 ; DC. ! prodr. 7. p. 172. Barkhausia 

 elegans, Nutt. in trans. Amer. phil. soc. I. c. p. 435. 



On the Assiniboin River, Drummond ! — Plant 6 inches high ; with rather 

 smaller heads than the preceding; the young achenia similar to those of that 

 species, and not more rostrate. 



6. C. acuminata (Nutt.) : perennial ; .stem nearly glabrous, sparingly 

 leafy, bearing numerous 8-10-flowered heads in a naked and fastigiate com- 

 pound corymb ; leaves pubescent, lanceolate ; the radical runcinate- 

 pinnatifid, tapering at the base into a petiole, and at the apeX into a slender 

 entire acuraination ; the cauline few and sessile ; the uppermost narrowly 

 linear, entire ; calyculate involucral scales villous-pubescent when young. — 

 Nutt. ! in trans. Amer. phil. soc. I. c. p. 437. 



Plains of the Platte, Nuttall! — Root long and fusiform. Scapiform stem 

 a foot high. Radical leaves 4-5 inches long. Heads more slender than in 

 C. nana; the young achenia, pappus, &c. similar. 



193. TROXIMON. Nutt. in Fras. cat. 1813, c^ gen. 2. p. 127 ; not of Gcertn. 



Agoseris, Raf. (excl. char.) — Ammogeton, Schrad. 



Head many-flowered. Scales of the campanulate involucre ovate-lan- 

 ceolate, acute or acuminate (distinct or nearly so), membranaceous, some- 

 what loosely imbricated in 2-3 series ; the exterior sometimes shorter. Re- 

 ceptacle subalveolate, rarely with a few chaffy scales intermixed among the 

 flowers! Achenia glabrous, oblong-linear, somewhat obcompressed, 10- 

 ribbed, with a large basilar callus, more or less narrowed at the apex, but 

 scarcely if at all rostrate. Pappus longer than the achenium, consisting 

 of copious and unequal rather rigid white bristles, in several series, scarcely 

 scabrous, the stronger ones gradually thickened towards the base, and fre- 

 quently more or less flattened. — Perennial acaulescent herbs, with the aspect 

 of Scorzonera (natives of the Upper Mississippi and Missouri, the interior of 

 Oregon, Saskatchawan, &c.,) ; the naked simple scapes terminated by a large 

 head. Root fusiform or thickened. Leaves linear or lanceolate, elongated, 

 entire, denticulate, or rarely runcinate-pinnatifid. Flowers showy, yellow, 

 sometimes changing to purple or rose-color when old or in drying. 



We find a gradual transition from the typical species of Troximon to Macrorhyn- 

 chus, to which genus this bears nearly the same relation that Crepis does to Bark- 

 hausia. Even the nature of the pappus fails to furnish a very marked distinction, 

 although in Troximon it is more or less rigid. Indeed, were the genus founded on 

 T. cuspidatum alone, it would inevitably be referred to the subtribe ScorzonereaB ; 

 for all the bristles of die pappus in that species are somewhat flattened and wider 

 towards the base ; the inner and stronger ones so much so that they should rather 

 be termed palea than bristles. But this character is much less evident in the nearly 

 allied T. glaucum ; and in the other species the bristles are capillary, although rather 

 stift'. The remaining Troximon of Gsertner proving a Scorzonera, the name should 

 certainly be kept for the present genus. 



1. T. cuspidatum {VuTsh): somewhat tomenlulose when young; leaves 

 narrowly linear-lanceolate, attenuate-acuminnte, somewhat nerved, especially 



VOL. II. — G2 



