- OP ARTS AND SCIENCES. 71 



cioribus ; acheniis apice parum contractis ; pappo sat molli uniformi. 

 — Washington Territory, on Mount Paddo (formerly called Mount 

 Adams), Suksdoi-f. Oregon on Mount Hood or in the mountains 

 near it, L. F. Henderson. 



TROxniON GRACiLENS. Macrorhyncfius, inter perennes, T. auran- 

 tiaco proximum ; floribus etiam aurantiaeis ; foliis scepissime integerri- 

 mis flaccidis ; scapo ultrapedali ; pappo nulli ; rostro tenuissimo (liu. 

 4-5-longo) achenio f usiformi-lineari paullo longiore. — Cascade Moun- 

 tains of Oregon and Washington Terr., Lyall, Nevius, Saksdorf, Rocky 

 Mountains in N. Wyoming, Dr. Forwood. 



Var. ? Greenei. Humilius; foliis linearibus lineari-lobatis. — Scott 

 Mountains in Siskiyou Co., N. California, in dry open ground at 7,000 

 feet, Greene. 



The beak of the akene affords very good characters in this difficult 

 genus. I adopt the subjoined arrangement for the North American 

 species. * 



* TROXIMON, Nutt. ; Benth. & Kook. 



§ 1. EuTROxiMOx. Beak of the more or less linear akene either none or short 

 and thickisli, and traversed by the nerves of the body. 



* No beak, the sliort contracted summit of the akene similar in texture to the 

 body : involucral bracts tapering above into a slender acuniination : pappus 

 rigidulous. 



T. cuspiDATUM, Pursh, the earliest name published wltli a character. T. mar- 

 ginatum, Nutt. ; not a bad name, for the tomentum commonly persists on the 

 margins of tiie leaf. 



T. ALPESTRE, Gray. Vide supra. 



* * A firm and thickish lightly nerved beak, decidedly shorter tlian the body 



of the akene : involucral bracts not attenuate-acuminate. 



T. GLAUCUM, Nutt., Pursh. A widespread and polymorphous species ; of 

 wliich tiie following are leading varieties : — Var. parviflorum, T. parvijiomm, 

 Nutt. Var. laciniatum, with forms on the one hand dilYering from T. parmjlo- 

 rum only in the laciniate-pinnatifid leaves, but in the Sierra Nevada with stouter 

 and cinereous-pubescent forms, some approacliing the next. Var. dasycepha- 

 LUM, to the synonyms of whicli in Flora N. America should probably be added 

 T. pumilum, Nutt., as well as T. taraxicifolium. At least tliere are dwarf as well 

 as large and robust forms. 



§ 2. Macrorhynchus. Akenes with a slender and nerveless (commonly fili- 

 form) beak. 

 * Perennials ; the akene with acute or pointed beak-bearing apex. 

 +- Beak little or no longer than the cylindraceous or narrowly fusiform akene. 



++ Flowers orange or reddish. 

 T. AURANTiACUM, Hook. T. roscum, Nutt., imperfectly known, seems to be 



