COMPOSITE. (COMPOSITE FAMILY.) 245 



•*- *- Scales of the involucre narrow, thin and membranaceous: racemes mostly elon- 

 gated and numerous, funning a crowded ample panicle. (These all present in- 

 termediate forms, and should rather be regarded as one polymorphous 

 species.) 



32. S. rupestris, Raf. Stem smooth and slender (2° -3° high); leaves 

 linear-lanceolate, tapering to both ends, smooth and glabrous, entire or nearly so ; 

 paniele narrow ; heads very small ; rays very short. — Roeky river-banks, Ken- 

 tucky and Indiana. 



33. S. Canadensis, L. Stem rough-hairy, tall and stont (3° -6° high); 

 leaves lanceolate, pointed, sharply serrate (sometimes almost entire), more or less 

 pubescent beneath and rough above ; heads small ; rays very short. — Borders of 

 thickets and fields: very common. — Varies greatly in the roughness and hairi- 

 ness of the stem and leaves, the latter oblong-lanceolate or elongated linear- 

 lanceolate ; — in var. pr6ceka, whitish-woolly underneath ; and in var. scabra 

 also very rough above, often entire, and rugose-veined. 



34. S. serotina, Ait. Stem very smooth, tall and stout (4° -8° high), often 

 glaucous : leaves lanceolate, pointed, serrate, roughish above, smooth except the veins 

 underneath, which are more or less hairy ; rays short. — Thickets and low grounds ; 

 common. — Intermediate in character, and in the size of the heads and rays, 

 between the last and the next. 



35. S. gigantea, Ait. Stem stout (3° -7° high), smooth, often glaucous; 

 kaces quite smooth both sides, lanceolate, taper-pointed, very sharply serrate, ex- 

 cept the narrowed base, rough-ciliate ; the ample panicle pubescent ; rays rather 

 long. — Copses and fence-rows : common : — presenting many varieties, but with 

 decidedly larger heads and rays than in the preceding. Seldom very tall. 



§ 3. EUTHAMIA, Xutt. Corymfxisely much branched: heads small, sessile, in 

 little clusters which are crowded in fat-topped corymbs; the closely oppressed 

 scales of the involucre somewhat glutinous : receptacle fmbrilkite : rays 6 - 20, 

 short, more numerous than the disk-flowers: leaves narrow, entire, sessile, crowded 

 or fascicled in the axils. 



36. S. lanceolata, L. Leaves lanceolate-linear, 3 - 5-nerved ; the nerves, 

 margins, and angles of the branches minutely rough-pubescent ; heads obovoid- 

 eylindrical, in dense corymbed clusters; rays 15-20. — River-banks, &c, in 

 moist soil : common. — Stem 2° -4° high : leaves 3' - 5' long. 



37. S. tenuifblia, Pursh. Smooth, slender; leaves xery narrowly linear, 

 mostly \-neiTid, dotted: heads obovoid-club-shaped, in numerous clusters of 2 or 

 3, disposed in a loose corymb ; rays 6 — 12. — Sandy fields, Massachusetts to 

 Illinois, and southward : common near the coast. 



20. BIGELOVIA, DC. Rayless Goldex-rod. 



Heads 3 - 4-flowered, the flowers all perfect and tubular : rays none. Invo- 

 lucre club-shaped, yellowish ; the rigid somewhat glutinous scales linear, closely 

 imbricated and appressed. Receptacle narrow, with an awl-shaped prolongation 

 in the centre. Achenia somewhat obconical, hairy. Pappus a single row of 

 capillary bristles. — A smooth perennial; the slender stem (l°-2° high) sim- 

 ple or branched from the base, naked above, corymbose at the summit, bearing 



