Petadtes. COMPOSITE. 375 



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

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

 wood of the region. 



Var. angustif 61ia, 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. tridentata. — 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-flowered, 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. 



++ ++ Heads somewhat larger and broader, glomerate-paniculate, 7-14-flowered : involucre short- 

 campanulate; inner bracts more scarious : stems low, suffruticose. 



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



A. Bolanderi, 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, 14-flowered, mostly equalled or surpassed by one or two linear^subulate herbaceous 

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

 Mono Pass, in the eastern part of the Sierra Nevada, California, Bolander. 



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



A. cana, Pursh. 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 revolute : heads glomerate in a leafy contracted 

 panicle, 6-9-flowered, rarely 5-flowered, 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- 

 iumbiensls, 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- 

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

 Rothrock in Wheeler Bep. 366, 1. 13 ; Gray, Proc. Am. Acad. xix. 50. A. trifida, Gray, !. c. 

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

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



Tribe VIII. SENECIONLDE^I, p. 79. 



179. TUSSILiAG-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 deutate 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. PETASlTES, Tourn. Butter-Bur, Sweet Coltsfoot. (neWos, 

 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 



