190 COMPOSITE. (COMPOSITE FAMILY.) 



3. B. chrysanthemoides, Michx. Glabrous, often decumbent at base, 

 a foot or two high : leaves lanceolate, rather minutely and evenly serrate: heads 

 rather large, little or not at all nodding : outer involucre seldom surpassing the 

 inner, conspicuously surpassed by the oval or broadly oblong rays : akeues 2 to 

 4-awned. Wet grounds, across the continent ; on the plains around Denver. 



2. Akenes narrow, linear-tetragonal ; the outer shorter and more truncate than 

 the inner, which generally taper upward : outer involucre seldom foliaceous or 

 enlarged : leaves (in ours) all once to thrice 3 to 5-nately parted or divided, and 

 the rays inconspicuous or none. 



4. B. bipinnata, L. Primary and secondary divisions of the leaves 

 rather ovate or deltoid-lanceolate in circumscription, and the lobes mostly acute : 

 akenes oil slender, the inner ones 5 to 9 lines long, outermost moderately shorter 

 and thicker : awns 3 or 4, sometimes only 2. A common weed in waste 

 ground throughout the continent. Commonly known as " Spanish Needles." 



5. B. tenuisecta, Gray. A foot or two high, branched from the base, 

 sparsely hirsute or glabrous : leaves 2 to 3-ternately or pinnately dissected into 

 narrow linear lobes : heads on naked rather long and stout peduncles, many- 

 flowered, 4 or 5 lines high in flower : akenes glabrous, 2-atvned ; inner 5 lines 

 long, with tapering summit ; outermost 3 lines long, stouter and with broad 

 summit and usually short awns : rays yellow, mostly surpassing the disk. 

 PI. Feudl. 86. Along water-courses, Colorado, New Mexico, and Arizona. 



44. THELESPERMA, Less. 



Smooth and glabrous perennials: with opposite usually finely dissected 

 leaves, and pedunculate heads : the rays golden yellow. 



* Lobes of the disk-corollas linear or lanceolate, longer than the throat : pappus 

 evident: chaff of receptacle falling with and partly embracing the akenes. 



1. T. ambiguum, Gray. A foot high, spreading by creeping rootstocks, 

 rather rigid and naked above : leaves bipinnately divided into narrowly linear 

 or filiform lobes : bracts of the outer involucre 8, subulate-linear, almost equalling 

 or half the length of the inner, which are connate to or above the middle : rays 

 broad, over % inch long, rarely wanting : disk usually purple turning brownish : 

 outer akenes becoming coarsely papillose ; the stout pappus-scales not longer than 

 the width of the akvne. Proc. Am. Acad. xix. 16. T. jttifolium of most of 

 the Western Reports. From Montana to Colorado, New Mexico, and W. 

 Texas. 



2. T. gracile, Gray. More rigid, a foot or two high, from a deep root, 

 less branched, naked above : leaves once or twice 3 to 5-nately divided or 

 parted into filiform-linear or broader lobes, or some upper ones filiform and 

 entire: bracts of the outer involucre 4 to 6, very short, ovate or oblong; of the 

 inner one connate to above the middle, the edges of their lobes slightly scari- 

 ous : disk mostly yellow, scarcely brownish after anthesis : akenes less papillose 

 or roughened, the breadth of the summit exceeded by the subulate awns : rays itsu- 

 ally none, rarely present and 2 or 3 lines long, Loc. cit. Plains, Nebraska 

 and Wyoming to W. Texas and Arizona. 



