350 COMPOSITE CENTROMADIA 



LAGOPHTLLA 



backs: rays white, fan-shaped 3-lobed, their achenes glabrous or glabrate 

 short : j appus of the disk-flowers shorter than the achenes, of 10-12 unequ, 

 al palese, 5 of them oblong to lanceolate. On dry plains, southern Oregon- 

 to California. 



54 CENTROMADIA Greene Man. 196. 



Rigid branching annuals with some of the lower leaves pin- 

 natifid and the uppermost clustered around the sessile heads. 

 Upper leaves or their lobes pungently pointed. Heads many- 

 flowered; ray-flowers pistillate, numerous and in more than one 

 series ; disk-flowers perfect but mostly sterile. Bracts of the in- 

 volucre rounded on the back, concave and partly enclosing the 

 ray-achenes, acuminate and pungently pointed. Receptacle coni- 

 cal or convex, chafly. all the disk-flowers being subtended by 

 narrow and mostly quite distinct chafly scales. Ray-achenes 

 turgid, obovate-triangular, very oblique, the terminal areola from 

 the summit of the inner angle or face, and by gibbosity common- 

 ly intraapical, raised on a little apiculation' 



C. Fitchii Greene 1. c. Villous hirsute, somewhat viscid, above besei 

 with small scattered tack-shaped glands: stems stoutish, 6-20 inches high, 

 branching: leaves linear or subulate, 2-3 inches long, acute and pungently 

 pointed, some of the lower ones once or twice pinnately parted : heads 

 numerous, terminating the branches : bracts of the involucre subulate : 

 rays yellow, narrow, their achenes obovate- triquetrous : chaff of the convex 

 receptacle soft and pointless, villons : disk-achenes sterile, with a pappus 

 of 8-12 linear palese fringed or bearded at tip, somewhat united at base. 

 Dry plains, southern Oregon to California. 



55 LAGOPHYLLA Nutt. Trans. Am. Phil. Soc. vii, 390 

 Slender much branched annuals with narrow leaves and mid- 

 dle-sized heads with yellow, white or pink ray-flowers. Heads 

 jew-flowered; rays about 5, pistillate; disk-flowers 5 or 6, perfect 

 but sterile. Bracts of the involucre as many as ray-flowers, her- 

 baceous the margins infolded and enclosing their achenes. Re- 

 ceptacle flat, fimbrillate-hirsute in the centre, chaffy at the mar- 

 gin between the ray- and disk-flowers, the chafly scales 5-6, in a 

 single series, distinct. Achenes smooth, without pappus: of the 

 rays oblong-cuneiform, obcompressed, straight, nearly flat and 

 obscurely angled on the back. 



L. ramosissima Nutt. 1. c. Stem slender, paniculately much branched, 

 6-30 inches high : leaves entire, canescent with soft silky pubescence ; rad- 

 ical and lowest cauline oboyate-spatulate ; upper lanceolate or linear,ob- 

 tusei the short ones subtending the crowded heads linear-oblong, densely 

 ciliate with very soft, villous hairs: heads 3 lines high, crowded in small 

 and at length rather scattered irregular clusters : bracts of the involucre 

 3-4 lines long, comose-ciliate : rays yellow, closing in sunshine : achenes ob- 

 oyate-oblong, carinate down the inner face. Common on dry plains and 

 hill-sides, Brit. Columbia to California and Idaho. 



56 LAYIA H. & A. Bot. Beech. 148. 



Low annual or biennial herbs with mostly opposite leaves and 

 middle-sized heads of yellow or white flowers,. Heads many- 

 flowered : the ray-flowers 10-15, pistillate : those of the disk tubu- 



