488 COxMPOSIT^. Crepis. 



Grassy plains of the Platte, Nuttall. — Scape 1-2 feet high, 2-4 times dicho- 

 tomous. Heads fastigiate, resembling those of C. biennis ; from which this 

 species is distinguished by its mostly naked and slightly pubescent scape, 

 narrower and less scarious scales of the involucre, &c., as well as the much 

 more entire leaves. Some states seem to approach the following species, so 

 as only to be distinguished by the larger heads, and more or less pubescent 

 involucre. 



2. C. glauca : perennial, glabrous and glaucous throughout; leaves all 

 radical, thickish, spatulate-oblong, or nearly lanceolate, mucronate or some- 

 what acuminate, tapering to the base, unequally runcinate-toothed or runci- 

 nate-pinnatifid, or some of the leaves entire ; scape naked, twice or thrice 

 dichotomous, with minute bracts at the divisions; scales of the proper in- 

 volucre about 12, linear; the calyculate scales minute; achenia obscurely 

 angled, smooth, slightly attenuated towards the apex, as long as the pappus. 

 — Crepidium glaucum, Nutt. ! in trans. Amer. ■phil' soc. I. c. 



0. caulescens : not glaucous [?] ; stem with a cauline leaf at the first;- 

 division. — Crepidium caulescens, Nutt. I. c. 



Plains of the Upper Platte, Nuttall! Lieut. Fremont! July-Aug. — 

 Scapes about a foot high. Heads much smaller than in C. runcinata, about 

 30-flowered. Leaves"3-6 inches long, tapering into an indistinct or winged 

 petiole. Achenia strongly striate-ribbed, smooth. 



3. C. occidentalis (Nutt.) : perennial ? dwarf, canescent with a close fur- 

 furaceous pubescence; cauline leaves few, sessile, pinnately parted, with the 

 linear or lanceolate lobes often somewhat toothed ; the radical lanceolate, 

 acute, runcinate-pinnatifid, tapering into a petiole ; the short lobes toothed ; 

 heads (few) paniculate-corymbose; proper scales of the cylindrical involucre 

 8-10, linear-lanceolate, canescent, and sparsely hispid with blackish haira 

 intermixed ; the calyculate scales few and very short; achenia fusiform, not 

 angled or striate, as long as the pappus. — Nutt. ! in jour. acad. Philad. 7. 

 p. 29. Psilochaena occidentalis, Nutt. ! in trans. Amer. phil. soc. I. c. 



On the Oregon, near the Rocky Mountains, Mr. Wyeth ! Plains of the 

 Platte, Nuttall .'—A span high. Heads as large as in C. runcinata, about 

 20-flowered. Achenia probably all fertile, tapering to the apex, not rostrate. 

 Pappus grayish-white. 



§ 2. Involucre few-flowered, cylindrical ; the exterior calyculate scales very 

 short and oppressed : receptacle naked: achenia slender, 5-10-striate. — 

 Ph^casium, Cass., Reichenb. (Crepis § Leptotheca, Nutt.) 



4. C. nana (Richards.) : perennial, nearly acaulescent, depressed, very 

 glabrous and glaucous ; scapes numerous from the summit of the somewhat 

 fusiform caudex, clustered, bearing one or more about 14-flowered heads, 

 scarcely equalling the elliptical or roundish entire or sinuate-lyrate long- 

 petioled leaves ; achenia linear, narrowed at the apex, scarcely rostrate. — 

 Richards. ! aj)px. Frankl. journ. ed. 2. p. 92 ; Hook. ! appx. Parry's 2nd 

 voy. p. 397, t.l, &f fl. Bor.-Am.l. p. 297. Hieracium, dec, Gmel.fl. 

 Sibir. 2. p. 20, t. 7, f. 2 Sf 3. Prenanthes pygmsea, Ledeb. in mem. acad. 

 St. Petersb. b.p. 55.3. P. polymorpha, Ledeb. ! fl. Alt. 4. p. 144. (a. Sf (i.) 

 Barkhausia nana, DC! prodr. 7. p. 156. 



From the Arctic coast and islands ! to lat 64°, and on the northern Rocky 

 Mountains! (Also in Arctic Siberia !)— Scapes and leaves an inch or two in 

 height ; the lamina of the inner leaves often oblong-linear. Corolla yellow, 

 turning purplish in drying. Achenia all uniform, or the central perhaps a 

 little longer than the marginal, 10-striate, a little constricted at the apex, and 

 then dilated into a disk that bears the pappus ; certainly none of them ros- 

 trate as in Barkhausia ! 



