Troximon. COMPOSITiE. 437 



flowers. — Nutt. in Fras. Cat. «fc Gen, ii. 127; Benth. & Hook. Gen. ii. 522; 

 Gray, Proc. Am. Acad. ix. 215, Bot. Calif, i. 437, & Proc. Am; Acad. xix. 71, 

 Troximon & MacrorhynclLUs (Less.), DC, Ton-. & Gray, Fl. ii. 489, 491. 



§ 1. EuTKoxiMOX. Akencs more or less linear, beakless, or tapering gradually 

 into a sliort and tliickisli beak, on wliicli the nerves or ribs of the body are pro- 

 longed to the apex : pappus rigidulous : perennial from a strong caudex. 



* No beak to the akeiie, its moderately short contracted summit of tlie same texture as the body 

 and eqiialh' 10-costate: involucral bracts somewliat equal, all tapering to a slender acumination, 

 the outer from an oblong or ovate-lanceolate base, glabrous: corolla yellow : root perennial. 



T. alpestre, Guay. Dwarf from an elongated rootstock or caudex, glabrous : leaves diverse 

 (2 or 3 iuches long), narrowly spatulate or lanceolate and pinnately lobed or incised, or 

 parted into narrow linear divisions : scape 2 or 3 inches high, weak : involucre canipaimlate, 

 7 or 8 lines high ; the bracts in about 2 series : akenes 2^ lines long, equalled by the slender 

 uniform pappus-bristles. — Proc. Am. Acad. xix. 70, 71. — On Mount I'addo, Washington 

 Terr., Huksdorf, 1880. Summit of Cascade Mountains, Oregon, L. F. Henderson. 



T. CUSpidatum, Pursh. Glaucescent, tomentulose when young, a span or two or the 

 scape at length a foot high from a thickened caudex : leaves entire, elongated linear-lanceolate 

 and upwardly linear-attenuate, thickish, often uervose, mostly tomentulose-ciliate (2 to 5 

 lines wide) : involucre about inch high; its bracts in 2 or 3 series: akenes 3 or 4 lines long 

 when mature, rather shorter than the unequal rigidulous pappus. — Fl. ii. 472 ; Torr. & Gray, 

 1. c. ; Gray, Man. 277, & Proc. Am. Acad. ix. 215. T. marijinatum, Nutt. 1. c. — Prairies of 

 \V. Illinois and Wisconsin to Dakota ; first coll. by Nuttall and Bradbury. Stronger pap- 

 pus-bristles gradually and slightly widened toward the base. 



* * Akenes with apex tapering gradually into a rather stout and nerved beak which is shorter 

 than the body. — § Nolkutruximon, Gray, Bot. Calif. 1. c, partly. 



T. barbellulatum, Grkexe in herb. Slender, not glaucous : leaves linear-lanceolate, 

 laciniate-pini atifi<l into a few sliort and narrow lobes, or some entire : involucre narrow, 

 over half-inch high, rather few-flowered ; its 10 to 12 bracts nearly equal, lanceolate, acumi- 

 nate, glabrous : flowei's yellow : akenes with the Ijeak (of fully half the length of the fusi- 

 form body) 3 lines long, about the length of the soft distinctly barbellulatc pappus. — Castle 

 Lake, near Mount Shasta, California, C. //. Dwinelle, from Greene. 

 T. glaucum, Nutt. Usually a foot or two high, rather stout, pale or glaucous, either 

 glabrous or with loose pubescence : leaves linear to lanceolate, from entire to sparingly 

 dentate or sometimes laciniate, 4 to 12 inches long: involucre commonly an inch high and 

 many-flowered ; its bracts lanceolate or broader ; outer series shorter, often pubescent, or 

 even villous : akenes with the beak 5 or 6 lines long, longer than the pappus, the copious and 

 rather rigid bristles of which are (as in most species) only denticulate-scabrous. — Nutt. in 

 Fras. Cat. & Gen. ii. 128 ; Pursh, 1. c. ; Sims, Bot. Mag. t. 1667 ; Torr. & Gray, 1. c. Macro- 

 rhijncliiis (ilaucus, Eaton, Bot. King P^xp. 204. — Grassy plains, Saskatchewan and Dakota to 

 Brit. Clolumbia, and mountains of Utah and Colorado; first coll. hy Nuttall and Bradbury. 



Var. parviflorum. ^V small and slender form : leaves only 2 to 6 inches long : scape 

 a span to a foot high : head smaller and narrower. — T. parviflorum, Nutt. Trans. Am. Phil. 

 Soc. vii. 434. Macrorhynchis cyntkioides, Hook Lond. .Jour. Bot. vi. 256 "? — Plains of Ne- 

 braska and Wyoming to the mountains of New Mexico. 



Var. laciniatum, Guay, Bot. Calif. 1. c. Dwarf (a span or two high), with the 

 small heads of the j)receding variety, varying to larger, glabrous or glabrate, when young 

 often cinereous-pubescent throughout : rays sometimes purplish externally or in fading : 

 leaves mostly of lanceolate outline and laciuiate-pinnatifid. — Mountains of Colorado and 

 New Mexico to the higlier Sierra Nevada, California. Larger forms pass into the next. 



Var. dasycephalura, Tokk. & Gray. Commonly robust, with large and broad 

 heads ; the involucre inch broad as well as high, and from villous to cinereou-s-pubescent, 

 sometimes early glabrate : receptacle not rarely bearing a few chaffy bracts among the flow- 

 ers : leaves from elongated-lanceolate to oblong-spatulate (the broadest even inch and a 

 half wide), from entire to laciniate or rarely pinnatifid : scape from a span to 2 feet high. — 

 — Ammogeton scorzonerivfoHum, Schrad. Ind. Sem. Ilort. Gcett. 1833; DC. Prodr. vii. 98. 

 Troximon glaucum, Richards. App. Frankl. Jour. ; Hook. Bot. Mag. 3462. T.pumilum, Nutt. 



