Petasites. COMPOSITE. 375 



most cuneate-linear : heads densely paniculate : involucre 5-8-flowcred, its outer or accessory 

 tomentose-canescent bracts short and ovate. Torr. & Gray, 1. c. ; Eaton, 1. c. Plains and 

 also on the drier mountains, Montana to Colorado, Washington Territory, and eastern slope 

 of the Sierra Nevada, California, immensely abundant, the characteristic Sage-brush or Sagc- 

 icood of the region. 



Var. angustifolia, GRAY. Leaves all narrow ; lower spatulate-linear, barely 3-toothed 

 at the roundish summit ; upper entire and more linear, a line or less wide : heads small : 

 shrub 3 or 4 feet high, with foliage too like that of the following species, but involucre of 

 A. tridcnfata. Proc. Am. Acad. xix. 49. Arid plains, S. Idaho and W. New Mexico to 

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

 A. trifida, NUTT. 1. c. A foot or two high, sometimes lower, much branched : leaves 3-cleft 

 and 3-parted ; the lobes and the entire upper leaves narrowly linear or slightly spatulate- 

 dilated : heads numerous in the contracted leafy panicle, or spicately disposed on its branches : 

 involucre 3-5-flowerecl, rarely 6-9-flowered, its outer or accessory bracts oblong to short-linear 

 or lanceolate. Torr. & Gray, Fl. ii. 419 (excl. var.) ; Eaton, 1. c. Plains and valleys, 

 Wyoming and Utah to Washington Terr, and the Sierra Nevada, California. 



f-i- -H- Heads somewhat larger and broader, .glomerate-paniculate, 7-1 4-flowered : involucre short- 

 campanuhite; inner bracts more scarious: steins low. suffruticose. 



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



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

 acutish, entire, or some with one or two slender lobes : heads numerous, densely glomerate- 

 paniculate, 1 4-flowered, mostly equalled or surpassed by one or two linear-subulate herbaceous 

 accessory bracts. Proc. Am. .Acad. xix. 50. A. trijida, in part, Gray, Bot. Calif, i. 405. 

 Mono Pass, in the eastern part of the Sierra Nevada, California, Do/under. 



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



A. cana, Prusn. A foot or two high, freely branched, silvery-canescent : leaves lanceolate- 

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

 2 or 3 acute teeth or lobes ; margins not rcvolute : heads glomerate in a leafy contracted 

 panicle, 6-9-flowered, rarely 5-flowercd, usually with one or two linear subulate accessory 

 bracts. Fl. ii. 521 ; Bess.' in Hook. Fl. & DC. Prodr. vi. 105; Torr. & Gray, 1. c. A. Co- 

 lumbicnsis, Nutt. Trans. Am. Phil. Soc. 1. c. Plains, Saskatchewan to Montana, Dakota, and 

 Colorado; common only northward. 



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

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

 upper linear, sometimes all entire: heads (2 or 3 lines long), glomerate-paniculate, 9-12- 

 flowcred : proper bracts of the involucre all ovate or oval, glabrate. Bot. Calif, i. 618; 

 Rothrock in Wheeler Rep. 366, t. 13 ; Gray, Proc. Am. Acad. xix. 50. A. tr(fida, Gray, 1. c. 

 405, in part. California, in the eastern and southern part of the Sierra Nevada, Rothrock, 

 Bolandcr, &c., and S. Utah, Ward, Parry. 



TRIBE VIII. SENECIONIDE^E, p. 79. 



179. TUSSIL.AG-O, Tourn. COLTSFOOT. (Tussis and ago, allays cough.) 

 - Single species, indigenous to Europe and Asia, naturalized in N. America. 



T. FARFARA, L. Low perennial herb, cottony-tomentose ; with extensively creeping root- 

 stocks, sending up in earliest spring a scape beset with alternate lanceolate bracts, and 

 terminated by a head of yellow flowers ; later developing rounded- or angulate-cordate irregu- 

 larly dentate leaves on long and stout radical petioles, glabrate in age. Wet grounds, a 

 common weed in N. Atlantic States and Canada. (Nat. from Eu.) 



180. PETASiTES, Tourn. BUTTER-BUR, SWEET COLTSFOOT. (ITeVao-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, 

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



