Pttasit.s. COMPOSITE. 



iiO 



most cnneate-linear : heads densely paniculate : involncre '>-5-fi '"tre^i. its outer or accessory 

 tomentufe-iaiie.-Meiit bracts short and ovate. — Terr, i Gray, 1. c; Eaton, 1. c. — Plains and 

 also on the drier mountains, :Montaua to Colorado, 'Washington Territorv, and eastern slope 

 of the ^icll.l Xevada, California, immensely abundant, the characteristic Stge-brush or >.i/t- 

 wood of the re^^iou. 



Var. angustif olia, Gkat. Leaves all narrow ; lower spatulate-linear, barely 3-toothed 

 at the roundish summit; upper entire and more linear, a liue or k>s wide: heads small: 

 shrub 3 or 4 feet liigh, with luli.i^e too like that of the foUowing sjjecies. but involucre of 

 A. Iridentata. — Proc. Am. Acad. xi.x. 49. — Arid plains, S. Idaho and AV. Xew 5Iexico to 

 the Mohave Desert and the southern borders of ^aii Diego Co., California. 

 ••A. triflda, Xutt. I. c. A foot or two high, sometimes lower, much branched : leaves 3-cleft 

 and 3-parte<-l : the lolies and tlie entire upper leaves narrowlv linear or slightlv spatidate- 

 dilated : heads numerous in the contracted leafy panicle, or jpicatcly disj.. psed on its brauches : 

 involucre 3-5-flowered, rarely 6-9-flowered, its outer or accessory 1 Tacts oblong to sliort-linear 

 or lanceolate. — Torr. i Gray, Fl. ii. 419 (exd. var.); Eaton, 1. c. — Plains and valleys, 

 Wyoming and Utah to Washiustou Terr, and the >ierra Xevada, California. 



■H- T-r Heads somewhat larger and broader, glomerate-paniculate, 7-14-rlowered: tnvolacre short- 

 campanulate; inner bracts more scariuus; stems low, suiiYuticose. 



= Pubescence looser, furf uraceous-tomentose : inner bracts of the involucre narrow. 



A. Bolanderi, Gkat. A foot or two high : leaves all narrowly linear, half a line wide, 

 acutish. entire, or some with one or two sleuder lobes : heads mmierous, densely glomerate- 

 paniculate, 14-fiowered, mostly equalled or surpassed by one or two linear-subulate herbaceous 

 accessory bracts. — Proc. Am. Acad. xix. 50. — A. tf'ji'hi. in part. Gray, Bot. Calif, i. 405. — 

 Mono Pass, in the eastern part of the sierra Xevada, California, Bolander. 



^^ = Canesceut pubescence minute and very close : bracts of the involucre broad. 



, A . cana, Puksh. A foot or two high, freely branched, silvervK^anesceiit : leaves lanceolate- 

 linear or narrower, somewhat tapering to both eniU, an inch or two long, entire, rarely with 

 2 or 3 acute teeth or lobes : mari'ins not revolute : heads glomerate in a leafy contracted 

 panicle, 6-9-£lowered, rarely .5-flowered, usually with one or two linear subulate aeeess' ry 

 bracts. — II. ii. rnl : Bess.' in Hook. Fl. & DC. Prodr. vi 105 : Torr. i Gray, 1. c. -1. C'o- 

 lumbiensis, Xutt. Trans. Am. Phil. Soc. L c. — Plains, Saskatihen an to Montana, Dakota, and 

 Colorado : common only northward. 

 A. Rothrockii, Geat. A foot or less high, less canescent or cinereous : leaves (inch or 

 less long) from cuneate and obtusely 3-lobed at dUated summit to spatulate-laneeolate or the 

 upper linear, sometimes all entire: heads i2 or 3 lines luugi. glomerate-panienlate, 9-12- 

 iiowered: proper laacts of the involucre all ovate or oval, glai^rate. — Bot. Calif, i. 61 S ; 

 Rotlirock in Wheeler Eep. 366, t. 13 ; Gray, Proc. Am. Acad. xix. 50. .1. trilida. Gray, 1. c. 

 405, in jjart. — California, in the eastern and southern part of the sierra Xevada, Rothrock, 

 Boiaii'Jer. ic, and S. Utah, Ward, Parri/. 



Tribe Till. SEXECIOXrOE^E. p. 



rft. 



179. TUSSILiAGO, Tourn. Colt-foot. (Tussis ani a^o. allajs cough.) 

 — Sin:;le speeiei. indigenous to Europe and A?ia. naturalized in X. America. 



'T. F.iEFAiLi, L. JLow perennial herb, cottony-tomentose ; with extensively creeping root- 

 stocks, sending up in earliest spring "a scape beset with alternate lanceolate bra/ts. and 

 terminated by a head of yellow flowers : later develojiing rounded- or angnlate-cordate irregu- 

 larly dentate leave^ on long and stout radical petioles, glabrate in age. — Wet giouii'is, a 

 common weed in X. Atlantic .--t.ires and Canada. (Xat. from En.) 



180. PETASlTES. Tourn. Buttek-Buk. Sweet Colt-foot. (mVao-os, 

 a broad-brimmed hat, alluding to the large and broad leaves.) — Perennial herbs, 

 of the northern temperate zone ; with thickish and mostly creeping rootstocks, 

 sendino- up scapiform and foliose-bracteate simple flowering stems, and ample 



