122 COMMON CANADIAN WILD PLANTS. 



petioles. Scales of the inversely conical involucre all ap- 

 pressed, and tipped with very short green points. — Woods 

 and along fences. 



6. A. sagittifo'liUS, Willd. Eays pale blue or purple. 

 Heads small, in dense compound racemes or panicles. Stem 

 smooth or nearly so, erect, with ascending branches. Leaves 

 conspicuously serrate, ovate-lanceolate, pointed, pubescent, 

 the lowest on long margined petioles, the upper lanceolate 

 or linear, pointed at both ends. Scales of the oblong invo- 

 lucre linear, tapering into awl-shaped, slender and loose 

 tips. — Thickets and along fences. 



7. A. Lindleya'nUS, Torr. and Gr. Bays pale violet. 

 Stem rather stout, smooth or sparsely pubescent. Leaves 

 conspicuously serrate. Eoot-leaves and lowest stem-leaves 

 ovate, more or less cordate, with margined petioles ; upper- 

 most sessile, and pointed at both ends. Seads rather small, 

 in a loose thyrse or panicle. Scales linear, green-tipped. — 

 Open barren grounds. 



* • Upper leaves all sessile or clasping by a heart-shaped base ; lower 

 ones not heart-shaped. 



8. A. ISBViS, L. Mays large, sky-blue. Very smooth 

 throughout. Heads in a close panicle. Leaves lanceolate 

 or ovate-lanceolate, chiefly entire, rough on the margins, 

 the upper ones clasping hy an auricled base. — Dry woods. 



9. A. Novse-An'glise, L. Eays many, narrow, violet- 

 purple, showy ; heads large. Involucre of many slender equal 

 scales, apparently in a single row, clammy. Stem stout, 3-8 

 feet high, hairy, corymbed above. Leaves very numerous, 

 lanceolate, entire, clasping by an auricled base, pubescent. 

 — River-banks and borders of woods. 



10. A. puni'eeUS, L. 2Joy« Zojigr, lilac-blue. Scales of the 

 involucre narrowly linear, loose, in about two rows. Stem 

 3-6 feet high, stout, rough-hairy, usually purple below. 

 Leaves oblong-lanceolate, clasping by an auricled base, 

 sparingly serrate in the middle, rough above, smooth 

 beneath, pointed. — Swamps; usually clustered. 



