COMPOSITE. (COMPOSITE FAMILY.) 197 



St. A. acuminatUS, Michx. Somewhat hairy; stem (about 1° high) 

 simple, zigzag, panicled-corymbose at the summit; peduncles slender; leaves 

 oblong-lanceolate, conspicuously pointed, coarsely toothed above, wedge-form and en- 

 tire at the base ; scales of the involucre few and loosely imbricated, linear-lan- 

 ceolate, pointed, thin (3"- 5" long); heads few or several; rays 12-18, white, 

 or slightly purple. — Cool rich woods, common northward and southward along 

 the Alleghanies. Aug. — There is a depauperate narrow-leaved variety on the 

 White Mountains of New Hampshire. 



35. A. nemoralis, Ait. Minutely roughish-pubesccnt ; stem slender, 

 simple or corymbose at the summit, very leafy (l°-2° high) ; leaves small (1'- 

 l£' long), rather rigid, lanceolate, nearly entire, with revolute margins; scales of the 

 inversely conical involucre narrowly linear-lanceolate, the outer passing into 

 awl-shaped bracts; rays lilac-purple, elongated. — Bogs, pine barrens of New 

 Jersey to Maine along the coast, and northward. Also White Mountains of 

 New Hampshire ; a small form, with solitary heads. Sept. 



36. A. ptas-micohles, Torr. & Gr. Smooth or roughish ; stems clus- 

 tered (6' -15' high), simple; leaves linear-lanceolate, acute, rigid, entire, tapering 

 to the base, 1 -3-ncrved, with rough margins (2' -4' long) ; heads small, in ajlat 

 corymb: scales of the involucre imbricated in 3 or 4 rows, short; rays white 

 (2" -3" long). — Dry rocks, W. Vermont to Wisconsin along the Great Lakes, 

 Illinois, and northward. Aug. 



$ 6. OXYTRIPOLIUM, DC. — Scales of the involucre imbricated, without herba- 

 ceous tips, usually very acute, the outer passing into scale-like bracts: pappus soft 

 and capillary: achenia striate. 



37. A. flcxnostis, Nutt. Stem zigzag, rigid, forked (6' -20' high) ; the 

 branches bearing large solitary heads ; leaves linear, thick and fleshy, pointed, entire ; 

 6cales of the bell-shaped involucre imbricated in many rows, ovatc-lanccolatc with 

 awl-shaped points ; rays numerous, large, pale purple. — Salt marshes, on the 

 coast, Maine to Virginia. Sept. 



38. A. lklifoliHS, L. Stem much branched (6'- 24' high), the branches 

 bearing numerous racemose or panicled small heads; leaves linear-lanceolate, pointed, 

 entire, flat, on the branches awl-shaped ; scales of the oblong involucre linear-awl- 

 shaped, in few rows ; rays someivhat in two rows, short, not project inq beyond the disk, 

 more numerous than the disk-flowers, purplish. (A. sububitus, Michx.) — Salt 

 marshes, on the coast, Maine to Virginia. 



14. ER5GEROK, L. Fleabaxe. 



Heads many-flowered, radiate, mostly flat or hemispherical ; the narrow rays 

 very numerous, pistillate. Scales of the involucre narrow, nearly e^ual and 

 almost in a single row. Receptacle flat, naked. Achenia flattened, usually 

 pubescent and 2-nerved. Pappus a single row of capillary bristles, with minuter 

 ones intermixed, or with a distinct short outer pappus of little bristles or chaffy 

 scales. — Herbs, with entire or toothed and generally sessile leaves, and solitary 

 or coryrnbed heads. Disk yellow: ray white or purple. (Name frcm qp. 



17* 



