COMPOSITAE (COMPOSITE FAMILY) 497 



arachnoid-ciliate or -lanate. (C. collinus Greene, Pitt. 3: 24. 1896.) North- 

 ern New Mexico to Wyoming, and Utah. 



13. Chrysothamnus wyomingensis A.- Nels. 1. c. 374. Tufted, 2-4 dm. 

 high, bushy-branched from the base, the branches with ascending or erect, 

 yellowish-green branchlets, with a thin inconspicuous tomentum throughout : 

 leaves 4-6 cm. long, narrowly linear, viscidulous as are also the branchlets: 

 inflorescence a narrow thyrsiform panicle, at maturity barely surpassing the 

 uppermost leaves: heads about 12 mm. high; bracts few, mostly acute or 

 acutish, glandular on the greenish keel: corolla obscurely short-pubescent be- 

 low: style branches exserted, the appendages longer than the stigmatic por- 

 tion. Frequent in Wyoming and extending into Colorado and probably 

 Utah, on saline soils. 



14. Chrysothamnus Parryi (Gray) Greene, Erythea 3: 113. 1904. Stems 

 rather strict, leafy to the summit: leaves linear to broadly linear, 5-8 cm. 

 long, obscurely 3-nerved, glabrous; the upper ones hardly diminished in size 

 and overtopping all the heads of the strict and narrow thyrsiform-virgate pan- 

 icle: heads 12-15 mm. long, 10-15-flowered; bracts of the involucre about 12, 

 lanceolate and gradually acuminate, rather prominently 1-nerved, thin- 

 chartaceous, a few exterior ones tapering into a prolonged subulate-linear her- 

 baceous appendage. Mountain parks; southern Wyoming and in Colorado. 



15. Chrysothamnus oreophilus A. Nels. 1. c. 375. Green and nearly gla- 

 brous, 2-4 dm. high; stems several to many, strictly erect and somewhat 

 fascicled, grayish with a thin tomentum, the annual twigs also fascicled-erect, 

 slender and yellowish-green: leaves erect, linear-filiform, very acute, canalic- 

 ulate, green and glabrate, 3-5 cm. long: heads small (about 1 cm. high), in 

 small fastigiate cymes; bracts oblong, abruptly subacute, only 2 or 3 in each 

 vertical row, the scarious margins ciliate-pubescent : corolla sparsely short- 

 hairy; lobes distinctly glandular-thickened at apex: style appendages longer 

 than the stigmatic portion: the short achene finely pubescent. (C. pinifolius 

 Greene, Pitt. 5: 60. 1902.) Mountain slopes; Wyoming, Colorado, and Utah. 



16. Chrysothamnus pulcherrimus A. Xels. 1. c. 370. Shrub 5-12 dm. high, 

 main stem and branches with grayish bark, the season's stems yellow but 

 under the lens minutely lanate-puberulent, rather slender-virgate, termina- 

 ting in an ample, compact, paniculate cluster: leaves narrowly linear, rather 

 lax and spreading, 5-8 cm. long, from white-tomentose to greenish-glabrate: 

 involucral bracts only 2 or 3 in each row, oblong, acute, nearly glabrous, 

 ciliate on the margins: corolla-tube longer than the throat into which it grad- 

 ually expands, rather closely short-hairy : anthers well exserted, the append- 

 ages of the style exceeding these: achene softly pubescent. Near streams; 

 from Colorado to Montana. 



17. Chrysothamnus plattensis Greene, Pitt. 4: 42. 1899. Low and merely 

 suffrutescent, 15-30 cm. high, very leafy, the long, narrowly linear, white- 

 tomentose leaves spreading or recurved: involucral bracts about 3 in each 

 vertical rank, acute, glabrous except that the margins are rather densely 

 woolly-ciliate: tube of corolla somewhat pubescent; throat elongated, rather 

 deeply cleft. Abundant on alkali plains adjacent to the Plat'te and its trib- 

 utaries in Colorado and Wyoming. 



18. Chrysothamnus frigidus Greene, Erythea 3: 112. 1894. In dense 

 clumps, freely branched, 2-4 dm. high; branches of the season erect, numer- 

 ous, whitish-tomentose : leaves narrowly linear, 3-5 cm. long, acute, erect or 

 ascending, distinctly white-tomentose, seldom glabrate: heads mostly thyrsoid- 

 panicled, 8-10 mm. high; bracts in not very distinct vertical ranks, the outer 

 acute, the inner obtusish, all more or less tomentulose and glandular, the 

 margins delicately ciliate at least near the summit: corolla-tube sparingly 

 short-hairy, rather deeply cleft. Very abundant on the high plains of Col- 

 orado and Wyoming. 



The relationship of C. leucodadws, C. laetevirens, C. falcatus, and C. virens, published by 

 Dr. K. L. Greene in Pitt. 5: 59-62, is not known. They seem to have been collected only by 

 the author of the species, the first three at Grand Junction and the last at Canon City, Colo- 

 rado. 



ROOKY MT. EOT. 32 



