166 COMPOSITE. (COMPOSITE FAMILY.) 



# # # Involucre less imbricated, hemispherical; the bracts partly greenish, in few 



ranks, with or without scarious margins : low-stemmed or acaulescent, from a 

 thick rootstock, with solitary or few pedunculate heads, % inch or more high : 

 leaves thickish and narrow. 



t Heads terminating short leafy stems which arise from creeping and woody 

 rootstocks: involucral bracts acuminate and mucronate-tipped : akenes oblong, 

 very villous. 



31. A. Parryi, Gray. Tomentose-pubescent and cinereous, a span high : 

 leaves mostly spatulate and obtuse with a mucronate point, an inch or more 

 long : heads usually solitary on peduncle surpassing the leaves, very broad: bracts 

 of the involucre oblong-lanceolate, densely cinereous-pubescent : rays white, over 

 inch long. Am. Nat. viii. 212. Mountains of Wyoming. 



32. A. Xylorrhiza, Torr. & Gray. Less pubescent and glabrate, 4 to 8 

 inches high : leaves from narrowly spatulate-lanceolate to linear, 1 or 2 inches 

 long, 1 to 3 lines wide ; tlie upper commonly equalling the 1 to 3 peduncles : heads 

 smaller : involucral bracts more attenuate : rays " pale red " or " pale rose- 

 color," 4 lines long. Mountains of Wyoming. 



*- - Heads (large for the plant) solitary on simple and scapiform stems, which 

 with the cluster of narrow radical leaves rise from a thickened caudex: invo- 

 lucral bracts acutish : akenes linear, glabrate : pappus strongly denticulate. 



33. A. pulchellus, Eaton. Stems 2 to 4 inches long: radical leaves 

 from spatulate to narrowly linear, 1 to 2 inches long, obtuse, in our form only 

 a line wide : akenes striate. Bot. King. Exp. 143. Alpine from Wyoming 

 and Montana to Oregon and Washington Territory. 



# # * * Involucre little imbricated, with peduncles and upper part of stem viscid- 



glandular : heads % inch high, with conspicuous violet or purple rays. 



34. A. pauciflorus, Nutt. Stem 6 to 20 inches high from a slender 

 creeping rootstock, simple and bearing few heads, or branching above : leaves 

 moderately fleshy, linear, or radical subspatulate or elongated-lanceolate, 

 uppermost reduced to bracts : bracts of short hemispherical involucre rather 

 fleshy and green, moderatelv unequal and rather loose, in only 2 or 3 ranks : 

 akenes narrow, compressed, striate-nerved, appressed-pubescent. In saline 

 soil from New Mexico and Arizona to Utah, and eastward to Dakota and 

 the Saskatchewan. 



4. Involucre of 2 or 3 series of linear nearly eqval bracts ; the outer foliaceous, 

 resembling the upper leaves: ray-flowers with the ligule generally wanting: 

 akenes narrow, not compressed, appressed-pubescent : pappus simple, very 

 soft. Cox YZOPSIS. 



35. A. angustus, Torr. & Gray. A span to a foot high, branching, 

 leafy-stemmed, nearly glabrous, except that the linear chiefly entire leaves 

 are somewhat ciliate : numerous rather small heads disposed to be racemose- 

 paniculate : bracts of the involucre acute : corolla of tbe ray-flowers reduced 

 to the tube and much shorter than the elongated style. Fl. ii. 162. Wet 

 saline soil from Colorado and Utah to the Saskatchewan and Minnesota. 



5. Involucre imbricated in many rows ; the bracts linear, coriaceous below, with 

 foliaceous spreading tips: rays numerous and conspicuous, violet or bluish 

 purple: akenes narrowed downward, compressed: receptacle honeycombed: 



