Sericocarpus. COMPOSITiE. 103 



in loose compound corymbs, mostly pedicellate and bibracteafe ; scales of 

 the obovoid involucre narrowly oblong, with aciuish slightly spreading tips ; 

 rays longer than the copious white pap|)us. — Nees, Ast. p. 151 ; DC. I I. c. 

 Conyza bifoliata, IVait. Car. p. :204. Aster tortifolius, Michx. ! fl. 2. p. 109 ; 

 Ell. ! si: 2. p. 341. 



ji. Cullinsii : leaves sparingly crenate-serrate. — Aster (Leucocoma) Col- 

 linsii, Nutt. ! in jour. arad. Philad. 7. p. 82. 



Barrens and dry pine woods, Vircinia ! and North Carolina ! to Florida ! 

 and Louisiana! p. Florida, Mr. Ware! Aug.-Se|)t. — Plant about 2 feet 

 high, branched above. Leaves 6-12 Hnes long, rigid. — Heads as large as in 

 S. conyzoides, seldom clustered. Flowers of the disk 10 or more. Achenia 

 short. — In a specimen collected in Virginia by Mr. Durand, the lower leaves 

 are sparingly crenate-serraie, and the others entire. 



4. S. Oregoncnsis (Nutt.): nearly glabrotis : leaves broadly lanceolate, 

 rather acute, entire, 1-nerved, veiny, both sides and esjieciallv the margins 

 scabrous : heads clustered in small compact corymbs ; scales of the turbinate 

 involucre oblong-linear, 1-nerved; rays longer than the (white) pappus; 

 achenia slender. — Nutt.! in trans. Anier. phil. soc. {n. ser.) 7. p. 302. 



Oregon, Nuttali ! — Plant apparently rather large and slout, somewhat 

 branched. Leaves 2-3 inches long, nearly half an incli wide, thickish, nar- 

 rowed at the base ; those of the branchlets small. Heads rather larger than 

 in the following species, about 15-flowered. Achenia not very densely silky, 

 nearly linear, fully half the length of the pappus. — We have reason to think 

 that this will prove a mere variety of the succeeding; yet the exscrted rays 

 may atTord a constant character. 



5. S. rigidus (Lindl.) : nearly glabrous; leaves oblong-spatulafe, or ob- 

 lanceolafe, obtuse, often mucronulate, entire, somewhat 3-nerved, veiny, 

 both surfaces very scabrous, the margins ciliate-scabrous; heads clustered 

 in small compact corymbs; scales of the turbinate involucre narrowly ob- 

 long or linear, 1-nerved ; rays shorter than the (white) papjius ; achenia 

 rather slender. — Lindl.! in Hook. fl. Bar.- Am. 2. p. 14, c^ in DC. I. c. ; 

 Nutt. ! I. c. {fi. Isevicaulis.) Galatella platylepis, Nees, in herb Am. 



Low hills and gravelly soil, Oregon, around Fort Vancouver, &c. Doug- 

 las ! Dr. Scouler! Nuttali! July-Aug. — Plant 1 to 2 feet high; the sim- 

 ple stems, or the few corymbose branches, terminated by small compact 

 corymbs. Leaves an inch in length, rigid. Heads about 15-flovvered, near- 

 ly as large as in S. conyzoides. Inner scales of the involucre about the 

 length of the disk, scarious; the exterior with somewhat squarrose greenish 

 tips. Rays inconspicuous, but perhaps always present, and fertile. Ache- 

 nia when mature about half the length of the papj)us, not very densely silky. 



26. ASTER. Tourn. inst. t. 174 ; Linn. gen. no. 954. (excl. spec.) 



Aster, Biotia, Tripolium, Heleastrum, & species of Calimeris, DC. 



Heads many-flowered ; the ray-flowers in a single series, pistillate ; those 

 of the disk tubular, perfect. Scales of the involucre more or less imbricated, 

 usually with herbaceous or foliaceous tips. Receptacle flat, alveolate, or 

 rarely naked. Appendages of the style (in the disk-flowers) lanceolate or 

 subulate, acute, rarely triangular or obtuse. Achenia usually compressed. 

 Pappus simple, of numerous, often unequal, scabrous capillary bristles. — 

 Perennial herbs, or rarely annual (Tripolium), chiefly natives of North 

 America. Leaves alternate, entire or serrate. Heads corymbose, panicu- 

 late, or racemose. Rays white, purple, or blue ; the corolla of the disk yel- 

 low, often changing to purple. 



