196 COMPOSIT^E. Aster. 



§ 7. ErigerIstrum. Involucre of Erigeron, i.e. broad, of very many and 

 narrow acute or attenuate bracts, all of the same length, herbaceous, with no dis- 

 tinction of body and tip : rays numerous and "narrow : pappus simple : heads soli- 

 tary, or rarely two, large, terminating the simple stem : this leafy to the top, in 

 which and in the acute style-tips the section differs from Erigeron, to which it 

 makes transition : arctic and subarctic si^ecies. 



A. peregrinus, Pursh. Tomentose-pubescent and glabrate, a spau to 20 indies high from 

 a thickish ci-eeping rootstock : leaves oblong-lanceolate or upper ovate-lanceolate, these 

 closely sessile by partly clasping base (inch or two long), either entire or sharply denticulate- 

 serrate : head half-inch high and broader : bracts of the involucre attenuate, tomentose- 

 pubescent or villous, not at all viscid or glandular : rays haK-iuch long, violet-purple. — 

 Fl. ii 556; Torr. & Gray, Fl. ii. 155; Herder in PI. Kadd. ii. 10, in part. A. Unalaschensis, 

 Less, in Linn. vi. 122. A. Tilesii, Wikstr. in Act. Holm. 1822, 13? A. salsuginosus, Hook. 

 Fl. ii. 7, in part. A. consanguinens, Ledeb. Fl. Ross, ii. 473 ? — Alaskan Islands to Arctic 

 coast; first coll. by Nelson. (Arct. E. Asia.) Has been confused with ^1. salsncjinosiis, 

 I-Jichards., now removed to Erigeron, which is naked-stemmed above, its involucre -viscidu- 

 lous-glandular and not villous. 



A. pygm^US, Lindl. Villous-pubescent and below glabrate, a span or less high and 

 loosely cespitose : stems assurgent from a slender rootstock or creeping base : leaves lingu- 

 late-lauceolate to linear, entire, obtuse, nearly veinless (mostly an inch long) : head about 4 

 lines high, solitary: bracts of the involucre spreading, linear, acute or obtuse, flaccid, 

 densely or sparsely villous: rays 30 or more, apparently violet. — Hook. Fl. ii. 6, & DC. 

 Prodr. V. 228 ; Torr. & Gra}', Fl. ii. 154. — Arctic sea-coast, Nicliardson, Roe, &c. Seemingly 

 connects with Erigeron grandifiorus ; but has subulate and very acute style-tips. 



§ 8. DcELLiNGERiA. Pcippus manifestly double ; outer setulose, i. e. of numer- 

 ous rigid and short bristles or squamelhe in a distinct series, inner of long capil- 

 lary bristles, some of which are usually clavellate-thickened at the tip : involucre 

 of § Orthomeris, i. e. bracts destitute of herbaceous tips and thin-coriaceous, 

 shorter than the disk: rays not numerous (8 to 13), always white: disk-corollas 

 barely yellowish : akenes mostly obovate, several-nerved : heads corymbosely cy- 

 raose (rarely solitary) at summit of stem or sparing branches, not large : leaves 

 mostly entire, not rigid, veiny : pappus becoming tawny. — Gray, Proc. Am. 

 Acad. xvi. 98. Diplostepkium, Cass. Diet, xxxvii. 486, not IIBK. Doellingeria, 

 Nees, Ast. 17G, excl. spec. Diplostephium, § 1, DC. Prodr. v. 272, exel. spec. 

 Diplopappus § Triplopappus, Torr. & Gray, Fl. ii. 182. (The most distinct sub- 

 genus, even worthy of generic rank, except for some transitions. A. obovatus, 

 Meyer, Rhinacti iia , Less., has similar pappus, but is otherwise as Xylorrhiza.) 



* Leaves acute or acuminate, all entire, generally green and almn.';t glabrous, with loose veins and 

 beneath a minute reticulation of veinlets (visible only under a lens): bracts of the short involu- 

 cre mostly obtuse: akenes tur^nd-obovate at maturity, glabrate or glabrous: pjippus rather 

 rigid, at least some of the longer bristles clavellate: disk-corollas deeply 5-lobed. 



A. umbellatus, Mill. Stem 2 to 7 feet high, generally tall and corymbose at summit, 

 very leafy, bearing numerous rather crowded cyniosely disposed bead.s : leaves lanceolate to 

 oblong-lanceolate (3 to 6 inches long), acuminate and with tajjering base : involucre hardly 

 longer than the akenes ; its bracts lanceolate-linear, rather obtuse : style-appendages del- 

 toid-ovate, acutish : stronger pappus-bristles delicately clavellate. — Diet. ed. 7, no. 2; Ait. 

 Kew. iii. 199; Iloffm. Phyt. Blatt. 74, t. B, f. 2. A. nm'/gdalinns, Lam. Diet. i. 305; 

 Michx. Fl. 109 ; Lindl. Bot. Reg. t. 1517. C/irijsopsis am'/gdalina, Nutt. Gen. ii. 153. Diplo- 

 stephium umhellatnin & D. amiigdalinnm, Cass. 1. c; DC. I.e. 272; DipJopiippus umbellatus, 

 and D. am'/gdalinns, partly, Torr. & Gray, I.e. 183. — Low grounds, Newfoundland, S. Lab- 

 rador, and Saskatchewan to Arkansas and Georgia ; the typical form commoner northward : 

 low forms witli Ijroader and more scabrous leaves common soutlnvard. 



