COMPOSITE. 75 



17. IVARDOS'MIA, Caas. SWEET COLTSFOOT. 

 N. palma'ta, Hook. Leaves rounded, somewhat kidney- 

 shaped, palmately 5-7-lobed, the lobes toothed and cut. Cedar 

 swamps and bogs. 



18. ASTER, L. STABWOBT. ASTER. 

 * Leaves, at least the lower ones, heart-shaped and petioled. 



1. A. COrymbo'suS, Ait. Rays white or nearly so. Heads in 

 corymbs. Stem slender, 1-2 feet high, zigzag. Leaves thin, 

 smoothish, sharp-pointed, coarsely serrate, all the lower ones on 

 slender naked petioles. Woodlands. 



2. A. macrophyTlus, L. Rays white or bluish. Stem stout, 

 2-3 feet high. Leaves thickish, rough, finely serrate, the lower 

 long-petioled. Heads in closer corymbs than in No. 1. Wood- 

 lands. 



3. A. azu'reus, Lindl. Rays bright blue. Heads racemed or 

 panicled. Stem roughish, erect, racemose-compound above. 

 Leaves entire or nearly so, rough ; the lower ovate-lanceolate, on 

 long petioles ; the upper lanceolate or linear, sessile. The latest 

 flowering of our Asters. Dry soil. 



4. A. undula'tus, L. Rays bright blue. Heads racemed or 

 panicled. Stem hoary with close pubescence, spreading. Leaves 

 with somewhat wavy margins, ovate or ovate-lanceolate, roughish 

 above, downy beneath ; the lowest cordate, on margined petioles ; 

 the upper with ivinged short petioles clasping at the base, or 

 sessile. Dry woods. 



5. A. COrdifolius, L. Rays pale blue or nearly white. Heads 

 small, profuse, panicled. Stem much branched. Leaves thin, 

 sharply serrate, the lower on slender ciliate petioles. Woods 

 and along fences. 



6. A. sagittifolius, Willd. Rays pale blue or purple. Heads 

 small, in dense compound racemes or panicles. Stem smooth or 

 nearly so, erect, with ascending branches. Leaves ovate-lanceo- 

 late, pointed, pubescent, the lowest on long margined petioles, 

 the upper contracted into a winged petiole, or lanceolate or linear. 

 Thickets and along fences. 



