Sericobarpus. COMPOSITE.-' 171 



heads small, terminating the branches, with violet or purplish or white rays ; 

 these usually infertile: fl. summer. — PI. Fendl. 71; Benth. & Hook. Gen. 

 ii. 269. 



P. Cotilteri, Gray, 1. c. Branched from near the base, glabrous or obscurely hispidulous- 

 puberulent, or the rigid spreading flowering branchlets .granulose-glandular : leaves all short, 

 rigid, mostly incisely dentate, those of the branchlets minute : involucral bracts oblong or 

 broadly lanceolate : rays conspicuous (quarter-inch long) and rather broad: pappus copious. 

 — S. Arizona, Palmer, Le.mm.on, Pringle, &c. Mohave Desert, California, Parish, Coulter, &c. 

 (Adj. Mex.) 



P. asteroides, Gray, 1. c. Scabro-puberulent, a foot to a yard high from a plainly annual 

 root: lower leaves spatulate or oblong, sometimes laciniate-pinnatifid, sometimes barely 

 dentate ; upper mostly linear and entire : involucral bracts lanceolate or linear : rays smaller 

 and narrower : pappus less copious. — S. W. Texas to Arizona, Wright, &c. (Adj. Mex.) 

 P. brevilixgulata, Schultz Bip., of Mexico, the remaining species, resembles P. asteroides, 



but is more slender, with narrower leaves, smaller heads, and small rays which hardly surpass 



the pappus. 



46. EREMlASTRUM, Gray. ('Ep^ua, desert, ao-rpov, star, i. e. Aster 

 of the desert.) — PI. Thurb. in Mem. Acad. v. 320 ; Benth. & Hook. Gen. ii. 270; 

 Torr. in Pacif. R. Rep. v. 361, t. 6. — Single species. 



E. bellioid.es, Gray, 1. c. Small winter annual, diffusely branched from the very base and 

 depressed, hirsutely hispid throughout : leaves linear-spatulate, entire (half-inch long) ; those 

 at the summit of the flowering branches loosely rosulate-involucrate around the solitary 

 heads, and passing into involucral bracts : rays oblong-linear, white, acutely 2-3-dentate 

 at the apex, 4 lines long : disk yellow. — On the desert near the Rio Colorado, borders of 

 California and Arizona ; fl. January and February, Thurber, Newberry, Schott, Painter, W. G. 

 Wright, &c, and borders of S. Utah, Parry. — Seldom, if ever, are the bristles of the pap- 

 pus combined in clusters so as to form laciniate palese. 



47. SERICOCARFUS, Nees. (Septra's, silky, /cap7ro's, fruit, the akenes 

 sericeous-pilose.) — Perennial herbs, of low or moderate stature (all N. American) ; 

 with alternate commonly entire and sessile leaves, and small heads usually fasci- 

 cled in a terminal compact cyme ; both disk and ray white or whitish, or the 

 latter changing in age to purplish : fl. midsummer. — Nees, Ast. 148 ; DC. Prodr. 

 v. 261 ; Torr. & Gray, Fl. ii. 101 ; Benth. & Hook. Gen. ii. 270. 



* Pappus ferruginous: leaves sparingly serrate, comparatively thin and veiny, and the radical 

 ones large. 



S. OOnyzoides, Nees, 1. c. A foot or two high, and slightly pubescent or glabrate : radical 

 and lowereauline leaves spatulate (2 to 5 inches long, tapering into a margined petiole), 

 obtuse; upper ones oblong-lanceolate : involucre turbinate, 18-20-flowered: rays rather short 

 and broad. — Conyza asteroides, L. Spec. ii. 861. Aster Maryland/ cus (Pluk. Mant.), Michx. 

 PI. ii. 108. A. conyzoides, Willd. Spec. iii. 2043. — Dry woodlands, common from Maine to 

 Ohio and south to Florida. 



# # Pappus white: leaves entire, firmer, smaller, obscurely veined, disposed to be vertical, mostly 

 , obtuse: green tips of involucral bracts short, seldom squarrose: stems more leafy. 



4— Atlantic species : akenes short, canescent-sericeous. 

 S. solidagineus, Nebs, 1. c. Green, almost glabrous : stems strict and slender, 2 feet 

 high, acutely striate-angled : leaves from linear to spatulate-lanceolate, an inch or two long ■ 

 heads mostly glomerate and sessile, narrow, rather few-flowered : involucral bracts oblong, 

 very smooth and rigid : rays at length elongated. — Conyza linifolia, L., 1. c. Aster Ameri- 

 canists albus, &c, Pluk. Aim. t. 79, fig. 2. A. solidagineus, Michx. 1. c. A. solidaginoides, 

 Willd. 1. c. Galatella obtusifolia, Lehm. Ind. Sem. Hamb. 1837. — Moist woodlands, Canada 

 to Tennessee, Alabama, and Louisiana. 



