254 coMPOSiT.^. (composite family.) 



•wing, or in the ray 3-winged, crowned witli a pappus of several minute bristles 

 and usually 2-4 longer awns. — Perennial and l)ush} -branched smooth herbs, 

 pale green, with the aspect of Aster ; the thickish leaves chiefly entire, often 

 turned edgewise. Flowers autumnal; disk yellow; rays white or purplish. 

 (Dedicated to James Bolton, an English botanist of the last century.) 

 * Heads middle-sized, loosely corymbed. 



1. B. asteroides, L'Her. Stems 2-8° high; leaves lanceolate; invo- 

 lucral scales acuminate ; pappus of few or many minute bristles and 2 awns 

 or none. (B. glastifolia, L'Her., the awned form.) — Moist places along 

 streams; Penn. to 111., and southward to Fla. Sept., Oct. — A'"ar. decukrexs, 

 Engelm., a large form with the leaves alate-decurrent upon the stem and 

 branches. Mo. (Eggert). 



2. B. latisquama, Gray. Heads rather larger ; involucral scales oblong 



to ovate, obtuse or mucronate-apiculate ; pappus-awns conspicuous. — W. Mo. 



and Kan. 



* * Heads small, panided on the slender branches. 



3. B. difFilsa, L'Her. Stem diffusely branched ; leaves lance-linear, those 

 on the branclilets very small and awl-shaped ; rays short, mostly white ; pap- 

 pus of several very short bristles and 2 short awns. — Prairies of S. 111. ( Vasey), 

 and southwestward. Aug. - Oct. 



23. TOWNSENDIA, Hook. 



Heads many-flowered, the numerous ray-flowers (violet to Avhite) in a single 

 series, fertile. Involucre broad, the lanceolate scariously margined scales im- 

 bricated in several series. Eeceptacle flat, naked. Achenes obovate or oblong, 

 flattened, Avith thickish margins and beset with forked-capitellate hairs ; pap- 

 pus a single row of long awns or coarse rigid bristles, or reduced in the ray to 

 chaffy scales. — Low scarcely caulescent herbs, with linear to spatulate entire 

 leaves and large heads. (Named for David Townsend, botanical associate of 

 Dr. Darlington of Penn.) 



1. T. sericea, Hook. Acaulescent silky-pubescent perennial; heads 

 sessile, solitary or few, i-1' high; ray-pappus mostly bristly. — Dry plains, 

 central Neb., north and westward. April, May. 



24. SERICOCARPUS, Nees. White-toppkd Aster. 



Heads 12 - 20-flowered, radiate ; the rays about .5, fertile (white). Involucre 

 somewhat cylindrical or club-shaped ; the scales closely imbricated in several 

 rows, cartilaginous and Avhitish, appressed, with short and abrupt often spread- 

 ing green tips. Receptacle alveolate-toothed. Achenes short, inversely pyr- 

 amidal, very silky ; pappus simple, of numerous capillary bristles. — Perennial 

 tufted herbs (1-2° high), with sessile somewhat 3-nerved leaves, and small 

 heads mostly in little clusters, disposed in a flat corymb. Disk-flowers pale 

 yelloAv. (Name from a-npiKSs, silky, and Kapnos, fruit.) 



* Pappus rusty ; leaves sparingly serrate, veiny, rather thin. 



1. S. conyzoides, Nees. Somewhat pubescent ; leaves oblong-lanceolate 

 or the lower spatulate, ciliate ; heads rather loosely corymbed, obconical (4 - 6" 

 long). — Dry ground ; Maine to Ohio, and southward. July. 



