COMPOSITE. (COMPOSITE FAMILY.) 141 



rigid scabrous fragile bristles, dirty or tawny, rarely white and soft. Perennials, 

 commonly with hispid or hirsute, or often glandular pubescence. 

 77. Crepis. Involucre few to many-flowered, somewhat imbricated, or more commonly a 

 series of equal bracts and some short calyculate ones. Akenes from columnar to 

 fusiform, 10 to 20-costate. Pappus of copious white and usually soft capillary bristles. 

 Annuals or perennials. 



= = Flowers from whitish or cream-color to violet or rose-red. 

 7S. Prenanthes. Heads 5 to 30-flowered, mostly nodding. Akenes terete or 4 to 5-angled, 

 commonly striate, with truncate summit. Pappus of copious rather rigid capillary 

 bristles, in one section from whitish to ferruginous. Leafy-stemmed perennials, with 

 paniculate or thyrsoidly disposed heads ; leaves dilated. 



79. Lygodesmia. Heads 3 to 12-flowered, erect. Akenes terete, obscurely few-striate or 



angled, commonly linear or slender-fusiform. Pappus of copious and usually unequal 

 capillary bristles, either soft or rigidulous, from sordid-whitish to white. Stems 

 mostly rush-like and striate; leaves narrow-linear or reduced to scales. Flowers 

 rose-colored. 



■h- •«+ Beak to the akenes distinct and slender : heads erect. 



80. Troximon. Heads many-flowered, solitary, terminating simple naked scapes. Invo- 



lucre campanulate or oblong, more or less imbricated. Akenes 10-costate or 10- 

 nerved, smooth, not muricate nor sculptured. Pappus white or whitish. Flowers 

 yellow, orange, or rarely purple. 



81. Taraxacum. Heads many-flowered, solitary, terminating simple and fistulous naked 



scapes. Involucre campanulate or oblong, a single series of nearly equal narrow 

 bracts, a little connate at base, and several or numerous calyculate bracts at the base. 

 Akenes oblong-obovate to fusiform, 4 to 5-costate or angled, muricate or spinulose, 

 the summit abruptly contracted into a filiform beak. Pappus soft and capillary, dull 

 white, no woolly ring at its base. Flowers yellow. 



82. Pyrrhopappus. Heads and involucre nearly of the last, terminating scapose or 



leafy stems or branches. Akenes oblong or linear-fusiform, about 5-costate or sulcate, 

 muriculate-rugulose, tapering abruptly into a long filiform beak. Pappus copious, 

 soft and capillary, fulvous or rufous, its base usually surrounded by a soft-villous 

 ring. Flowers yellow. 

 ■*- -i- -»- Akenes flattened : pappus of copious fine and soft capillary bristles : leafy-stemmed 

 plants, with more or less paniculate heads. 



83. Lactuca. 1 Involucre cylindraceous, or in fruit somewhat conoidal, several to many- 



flowered. Akenes obcompressed, and with a beak or narrowed summit, which is 

 more or less expanded at apex into a pappiferous disk. Pappus of bright white or 

 rarely sordid bristles, falling separately. 



1. VERNONIA, Schreb. Iron-weed. 



Perennial herbs, with alternate pinnately-veined leaves, and usually purple 

 or rose-colored flowers, sometimes varying to white. 



1 . V. fasciculata, Michx. Glabrous, or nearly so, 2 to 5 feet high : 

 leaves thickish, from linear to oblong-lanceolate, conspicuously spinulose-denticu- 

 late : heads numerous and crowded on the branches of the compound cyme : invo- 

 lucre (3 or 4 lines high) 20 to 30-flowered; its bracts all obtuse, or some of 

 the uppermost abruptly mucronate-acute. — From the Dakotas to Texas with- 

 in the eastern limits of our range, and eastward to the Mississippi States. 



1 The following Old-World genus has several species naturalized within our range : — 

 Sonchus. Involucre campanulate or broader, in age usually broadened and fleshy-thick- 

 ened at base, and becoming conical. Akenes obcompressed, destitute of beak or neck or 

 dilated pappiferous disk. Pappus of very soft and fine flaccid bristles, which fall more oi 

 less in connection, and commonly one or more stronger ones, which fall separately. 



