172 COMPOSITE. Sericocwrpus, 



S. tortifolius, Nees, 1. c. Cinereous-puberulent and somewhat scabrous : stems not angled, 

 a foot or two high : leaves conspicuously vertical by a twist, obovate or spatulate, short : 

 heads more corymbosely cymose and most of them pedicellate, somewhat turbinate : involu- 

 cral bracts more numerous and narrower, the innermost linear, puberulent : rays small. — 

 Conyza bifoliata, "Walt. Car. 204. Aster tortifolius, Michx. 1. c. ; Ell. Sk. ii. 341. A. scabrosus, 

 BertoL Misc. Bot. vii. t. 5. A. (Leucocoma) Collinsii, Nutt. Jour. Acad. Philad. vii. 82, a 

 form with leaves sparingly crenate-serrate {S. tortifolius, var. Collinsii, Torr. & Gray, Fl. ii. 

 102). — Dry pine woods and barrens, Virginia near the coast to Florida and Louisiana, flow- 

 ering later than the others. 



-t— -i— Pacific species : akenes more slender, less canescent. 



S. rigidus, Lindl. Green, from scabrous-pubescent to nearly glabrous : stems a foot or two 

 high, somewhat striate-angled : leaves oblong-lanceolate (an inch or two long), acute or 

 obtuse, hardly rigid : heads crowded, either short-pedicelled or glomerate, somewhat turbi- 

 nate, about 15-flowered: involucral bracts rather narrow and one-nerved: rays small and 

 short, but sometimes surpassing the disk. — Hook. Fl. ii. 14, & DC. 1. c. ; Gray, Bot. Calif, 

 i. 320. S. Oregonensis, Nutt. Trans. Am. Phil. Soc. n. ser. vii. 302, a form with larger rays 

 and rather large leaves. — Woods, Washington Terr, to the Sierra Nevada, California. 



48. ASTER, Tourn. Starwort, Aster. (Aor^p, a star, late Latin 

 name for these and similar radiate-flowered and Daisy-like plants.) — Herbs, 

 mainly of the northern hemisphere, and especially of North America, the larger 

 part perennial : fl. late summer and autumn. The yellow disk-flowers in several 

 species change to purple or rose-color. — L. Gen. ed. 1, 254 ; DC. Prodr. v. 261 ; 

 Torr. & Gray, Fl. ii. 103 ; Benth. & Hook. Gen. ii. 271, at least as to American 

 species ; Gray, Proc. Am. Acad. xvi. 97, <fc xvii. 164. 



The line between Aster and Erigeron is arbitrary. Aster is far the most difficult of our 

 genera, both for the settlement of the names of the species and for their limitation, in respect 

 to which little satisfaction has been attained as the result of prolonged and repeated studies. 

 For full reasons why the following Linnasan species subside, see Proc. Am. Acad. xvii. supra cit. 



A. divaricAtus, L. Founded, as to the specimen in the herbarium, upon the upper part 

 of a plant of A. corymbosus, Ait., wanting the cordate serrate leaves ; as to the plants of Pluke- 

 net and Gronovius, upon A. infvrmus, Michx. 



A. kIgidus, L. Founded wholly upon Clayton's plant as described in Fl. Virg. ; is a mere 

 synonym of A. linariifolius, L. 



A. linif6lics, L., and A. htssopif<5litts, L. Mant., belong to Galatella, and are not Amer- 

 ican. The plant of Gronov. Fl. Virg., referred to, is A. tenuifolius, L. 



A. Annuus, L., is well known as Erigeron annuus. 



A. versus, L., is Erigeron nudicaulis, Michx. 



A. mutAbilis, L. Not to be found in the Linna;an herbarium. In the first ed. of the Spec. 

 PI. was compared with an " A. serotinus," which was ne.itb.er published nor preserved in the her- 

 barium, has as a synonym a plant figured by Plukenet which is not preserved in his herbarium : 

 finally, in ed. 2, the character was reconstructed in a manner incompatible with the original 

 one, and before the Plukenetian synonym " Herm. Hort. Lugd. t. 67 " was introduced, which, 

 on the authority of the herbaria of Koyen and of Sherard, is A. Imvis, L., and the comparison 

 was changed to one with A. Tradescanti, L. A. mutabilis of later authors belongs to older- 

 named species. 



A. mIser, L. Founded wholly upon a much exaggerated figure in Dillenius, with fictitious 

 character, drawn from the plate. See A. vimineus, var. foliolosus. 



A. ciliAtus, Walt. Car. 209, is not at all identified. 



Series I., Perennials, with multicipital rootstocks or caudex, usually multiply- 

 ing by creeping subterranean shoots. 



§ 1. Amellastrum. Bracts of the broad involucre 2-3-serial, of slightly un- 

 equal length; outer foliaceous or herbaceous-tipped: akenes broad, obovate, 



