808 



COMPOSITAE (COMPOSITE FAMILY) 



A. azureus. 



938. A. Shortii. 



leaves rough, the lower ovate-lanceolate or oblong, heart-shaped, on long often 

 hairy petioles; the others lanceolate or linear, sessile, on the branches awl- 

 shaped ; involucre inversely conical. Copses and prairies, 

 w. N. Y. and Ont. to Minn., Mo., and southw. Sept., Oct. 

 Involucre much as in A. laevis, but smaller and slightly 

 pubescent. FIG. 937. 



21. A. Sh6rtii Lindl. Stem slender, spreading, nearly 

 smooth, bearing very numerous heads in racemose panicles ; 

 leaves smooth above, minutely pubescent 

 underneath, lanceolate or ovate-lanceolate, 

 elongated, tapering gradually to a sharp 

 point, all but the uppermost more or less 

 heart-shaped at base and on naked petioles, 

 none clasping ; involucre bell-shaped. 

 Cliffs and banks, w. Pa. to 111. , and southw. 

 Aug. -Oct. A pretty species, 1 m. high ; 

 leaves 0.5-1.5 dm. long. FIG. 938. 



22. A. undulatus L. Pale or somewhat hoary with close 

 pubescence ; stem spreading, bearing numerous heads in race- 

 mose panicles ; leaves ovate or ovate- 

 lanceolate, with wavy or slightly toothed 

 margins, roughish above, downy under- 

 neath ; the lowest heart-shaped, on margined petioles ; the 

 others abruptly contracted into short broadly winged peti- 

 oles which are dilated and clasping at the base, or directly 

 sessile by a heart-shaped base ; involucre obovoid, the 

 bracts less rigid. Dry copses, N. B. to Ont., Minn., and 

 southw. Aug.-Nov. FIG. 939. Very variable in outline 

 of leaves, etc., upon which characters Professor E. S. Bur- 

 gess proposes many species. 



w- -w- Leaves for the most part conspicuously serrate; rays 

 pale blue or nearly white. 



23. A. cordifblius L. Stem nearly glabrous, much 

 branched above, the spreading or diverging branches bearing 

 very numerous panicled heads ; leaves thin, sharply serrate, 

 minutely scabrous above; the lower all heart-shaped, on 



generally slender and naked ciliate peti- 

 oles ; the upper chiefly cordate ; bracts 



of the inversely conical involucre all 



oppressed and tipped with very short green 



points, obtuse or acutish. Woods and 



thickets, e. Que. to la. , s. to Ga. and Mo. 



Aug. -Oct. Heads profuse, but rather 



small. FIG. 940. Var. FuRBfsniAE Fer- 



nald. Stems, petioles, and lower surfaces 



of leaves densely villous. Banks of 



streams, N. B., Me., and N. H. Var. POLYCEPHALUS Porter. 



Most of the upper leaves truncate or narrowed at base. 



Range of the typical form. 



24. A. Lowrieanus Porter. Resembling A. cordifolius; 



leaves thickish, glaucous beneath, smooth, often greasy to the 



touch, sharply or obscurely serrate ; the lower ovate, cordate, 



on mostly winged petioles. Open woods and thickets, Ct. to 

 941. A. sagittifolius. Ont. and N. C. Sept., Oct. Var. LANCEOL\TUS Porter. Most 



of the lower leaves lanceolate or lance-ovate, truncate or nar- 

 rowed at base. (Var. lancifolius Porter.) Similar range. Var. mclsus Porter. 

 Leaves all lanceolate, the lower incised. (Var. Bicknellii Porter.) N. Y. and 

 Pa., local. 



25. A. sagittifblius Wedemeyer. Stem rigid, erect, smooth or slightly 



939. A. undulatus. 



940. A. cordifolius. 



