258 COMPOSITE, (composite family.) 



15. A. Concolor, L. Stems wand-like, nearly simple; leaves crowded, 

 oblong or lanceolate, appressed, the upper reduced to little bracts ; heads in a 

 simple or compound wand-like raceme; scales of the obovoid involucre closely 

 imbricated in several rows, appressed, rather rigid, silky, lanceolate ; achenes 

 silk I/. — Dry sandy soil near the coast, R. I., N. J., and southward. — Plant 1 - 

 3° high, with the short leaves V or less in length, grayish-silky both sides. 



* 4. Leaves entire, the lower not heart-shaped, the caul ine all loith sessile and 



cordate-claspinij base, the auricles generalltj meeting around the stem. 



16. A. patens, Ait. Rough-pubescent; stem loosely panicled above (1 - 

 3° high), with widely spreading branches, the heads mostly solitary, terminating 

 slender branchlets ; leaves oblong-lanceolate or ovate-oblong, often contracted 

 below tlie middle, rough, especially above and on the margins ; scales of the 

 minutely roughish involucre with spreading pointed tips ; achenes silky. — Var. 

 phlogif6lius, Nees, is a form of shady moist places, with larger and elongated 

 thin scarcely rough leaves, downy underneath, sometimes a little toothed above, 

 mostlv much contracted below the middle. — Dry ground ; common, Mass. to 

 Minn., and southward. Heads i' broad, with showy deep blue-purple rays. 



* 5. Loiver leaves heart-shaped and petioled ; no glandular or viscid pubescence ; 



heads ivith short and appressed green-tipped scales {except in n. 17 and 24), 

 viostlg small and numerous, racemose or panicled. 

 H- Heads middle-sized, with manij rags, and squarrose foliaceous involucre. 



17. A. anomalus, Engelm. Somewhat pubescent and scabrous ; stems 

 slender (2 - 4° high), simple or racemose-branched above ; leaves ovate or ovate- 

 lanceolate, pointed, entire, the upper small and almost sessile ; scales of the 

 hemispherical involucre imbricated in several rows, appressed, with linear 

 spreading leafy tips; achenes smooth. — Limestone cliffs, W. 111. and Mo. to 

 Ark. — Rays violet-purple. 



-t--t- Rags 10-20; involucral scales appressed or erect. 

 •(-»• Leaves entire or slightlij serrate; heads middle-sized ; rags bright-blue. 



18. A. azureus, Liudl. Stem rather rough, erect, racemose-compound 

 at the summit, the brandies slender and rigid; leaves rough, the lower ovate- 

 lanceolate or oblong, heart-shaped, on long often hairy petioles ; the others lanceo- 

 late or linear, sessile, on the branches awl-shaped; involucre inversely conical. 

 — Copses and prairies, western N. Y., and Ohio to Minn., and southwestward. 

 luTolucre much as in A. liBvis, but smaller and sliglitly pubescent. 



19. A. Shortii, Hook. Stem slender, spreading, nearly smooth, bearing- 

 very numerous heads in racemose panicles ; leaves smooth above, minutely pu- 

 bescent 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, Ohio 

 to 111., and southward. — A pretty species, 2-4° high ; leaves 3-5' long. 



20. A. undulatUS, L. Pale or somewhat hoary with close pubescence ; 

 stem spreading, bearing numerous heads in racemose panicles ; leaves ovate or 

 ovate-lanceolate, ivith wavy or slightly toothed margins, roughish above, downy un- 

 derneath, the lowest heart-shaped on margined petioles, the others abrupdy con- 

 tracted into short broadly winged petioles which are dilated and clasping at the 



