254 COMPOSITE. (COMPOSITE FAMILY.) 



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

 and usually 2-4 longer awns. Perennial and bushy -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 Bohon, 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; Perm, to 111., and southward to Fla. Sept., Oct. Var. DECURREXS, 

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

 branches. Mo. (Eayert). 



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

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



and Kan. 



* * Heads small, panicled on the slender branches. 



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

 on the branchlets 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. 



xleads many -flowered, the numerous ray-flowers (violet to white) in a single 

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

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

 flattened, with 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, |-1' high; ray -pappus mostly bristly. Dry plains, 

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



24. SERICOCARPUS, Nees. WHITE-TOPPED 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 whitish, 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-uerved leaves, and small 

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

 yellow. (Name from a-ripiKSs, silky, and Kapiros, 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. 



