178 COMPOSITE;. 



acute, white-pubescent ; lower tapering into a petiole, serrate ; branches 

 leafy ; racemes erect ; scales of the involucre obtuse. Aster bicolor Nees. 

 Spreng. 



Dry Hills. Can. to Geor. Aug. Oct. l\..Stem 12 feet high, erect, very 

 pubescent. Heads numerous, rather large, in short clusters, forming a long 

 dense leafy raceme along the upper part of the stem ; rays 7 9, nearly white. 



Two-colored Golden-rod. 



21. S. stricta Ait. : stem 'erect, smooth ; cauline leaves lanceolate, very 

 entire, smooth, scabrous on the margin ; radical tapering into winged peti- 

 oles, minutely serrate ; racemes paniculate, very erect ; peduncles smooth. 



Sphagnous swamps. Hudson's Bay to Mass, and N. Y. July, Aug. %. 

 Stem 24 feet high, virgate, purplish. Heads forming a dense stiffly erect pan- 

 icle which is leafy at base ; rays 5 6, rather small. Upright Golden-rod. 



22. S.virgata Mich. : stem smooth and simple, summit racemose ; leaves 

 smooth, lanceolate-oblong, somewhat obtuse, appressed to the stem, diapha- 

 nously punctate ; upper smaller and entire ; branches of the panicle elon- 

 gate, racemed at the summit ; peduncles erect, smooth, filiform and squar- 

 rose. 



Swamps. N. J. to Flor. Sept., Oct. Stem 2 4 feet high, much attenu- 

 ted. Leaves gradually diminishing upwards ; lower ones very large, serrulate. 

 Heads small. Long-branched Golden-rod. 



23. S, latifolia Linn. : stem angled, mostly flexuous, smooth ; leaves 

 broad-ovate or oval, coarsely dentate-serrate, very acuminate at both ends 

 or abruptly attenuate into a short petiole, mostly hairy on the veins be- 

 neath ; heads in short axillary racemes or clusters, racemose or paniculate 

 at the summit of the stem. & Jlexicaulis Ait. S. macrophylla Big. 



Moist woods. Can. to Geor. W. to Ken. Aug. Oct. i^.Stem 23 feet 

 high, usually simple. Heads middle-sized, in clusters or racemes; rays 3 4; 

 disk flowers 6 7. Broad-leaved Golden-rod. 



24. *S. cczsia Linn. : stem erect, smooth, glaucous, simple or branched; 

 leaves lanceolate or oblanceolate, acuminate, serrate, smooth ; heads in 

 short axillary clusters or racemes ; peduncles pubescent; involucres smooth. 

 ,$. Jlexicaulis Linn. S. axillaris Pursh. S. livida Wittd. 



Woods and thickets. Can. to Geor. Aug. Oct %. Stem 23 feet high, 

 slender, usually dark purple and glaucous. Heads middle-sized ; rays 34, 

 Allied to <S. latifolia, but probably distinct. Purple-stalked Golden-rod. 



25. S. rigida Linn. : stem erect, roughly pubescent, paniculate at the 

 summit ; leaves rigid, scabrous, slightly clasping ; lower oval, petioled, 

 crenate-dentate ; upper ovate-oblong, sessile, entire ; heads very large, in 

 compact erect racemes ; scales of the involucre obtuse. 



Rocky hills. Conn.and N. Y. to Car. W. to Texas. Aug. Oct. l\.Stem 

 3 4 feet high, rigid, very pubescent when young. Heads very large, many- 

 flowered, clustered near the summits of the branches ; rays 7 10, elongated. 



Rigid-leaved Golden-rod. 



26. S. Virgo- Aurea Linn. : stem erect, terete, pubescent and branching 

 at the top ; cauline leaves lanceolate, serrate, attenuate at each end ; lower 

 ones elliptic, petioled; racemes erect, simple or compound; scales of the 

 involucre linear-acute. 



