248 American Midland Naturalist Monograph No. 7 



ous, small, the branches of the panicle spreading; dry 

 woods, western and northern 111., extending south- 

 ward and eastward to Will and Macoupin counties. 

 Aug.-Oct. [A. cordijolius var. moratus Shinners]. Blue 



Wood Aster A. cordijolius L. 



7. Bracts attenuate, with a median green line; leaves lan- 

 ceolate to ovate-lanceolate, less serrate, the petioles 

 margined; panicle-branches ascending. 

 8. Stem glabrous, or sparsely pubescent along decurrent 

 lines on the upper part; leaves glabrous to sparsely 

 pubescent beneath; dry woods, common throughout 



111. Aug.-Oct. Arrow-leaved Aster 



- A. sa^ittifolius Wedem. 



8. Stem evenly and often rather copiously short-pubescent 

 throughout (except the base), varying to merely 

 hirtellous-puberulent or nearly glabrous; lower sur- 

 face of leaves finely and evenly short-pubescent 

 throughout ; dry open woods, common throughout 

 111. Aug.-Oct. [A. drummondii var. rhodactis 



Benke]. Drummond Aster A. drummondii Lindl. 



3. Leaves all or mostly entire or subentire, firm; rays purple. 



9. Bracts erect, appressed; involucre campanulate, 5-7 mm 

 high; rays 12-15. 

 10. Bracts and peduncles pubescent; stem nearly equally 

 leafy throughout; leaves glabrous or nearly so above, 

 sparingly pubescent beneath; rays 10-12 mm long; 

 banks and dry open woods nearly throughout 111. Aug.- 

 Oct. \A. shortii f. groneynanni Benke].. A. shortii Lindl. 

 10. Bracts glabrous, with conspicuous rhombic green tips; 

 leaves thickish, firm, scabrous on both sides, those of 

 the upper part of the stem and of the branches bract- 

 like, linear, cuspidate; rays 6-8 mm long; sandy soil 

 and in open woods nearly throughout 111. Sept. -Oct. 



[A. azureus f. laevicaulis Fern.] A. azureus Lindl. 



9. Bracts spreading or recurved, scabrous-pubescent, lanceolate, 

 acuminate; involucre hemispherical, 8-12 mm high; rays 

 30-45, 10-12 mm long; bluffs and rocky woods in and near 

 the Mississippi valley northward to Hancock Co.. and in 

 the Illinois valley as far as Peoria and Woodford counties. 

 Sept.-Oct A. anomalus Engelm. 



2. Lower leaves not cordate. 



11. Stem leaves clasping or auricled at the base (only slightly 

 in A. oblongijolius) . 

 12. Stem pubescent or puberulent throughout, or at least 

 above. 

 13. Leaves all entire or essentially so. 



1 4. Heads numerous, subcorymbose ; involucre hemi- 

 spherical, the bracts minutely glandular. 



