796 coMPOsiTAE (composite family) 



4-7 cm. long, 1-2 cm. broad. — Dry or sterile situations, Gasp6 Co., Que.; and 

 from 111. to Man., Kan,, and westw. 



42. S. rupestris Raf. Stem smooth, slender, 5-10 dm. high ; leaves linear- 

 lanceolate, tapering both ways, enti7'e or nearly so, glabrous upon both surfaces; 

 racemes ascending, scarcely recurved, forming somewhat open or elongate pan- 

 icles ; pedicels slightly pilose or glabrate. — Rocky river-banks, W. Va., Ky., 

 and Ind. Aug., Sept. — Too near the preceding, of which it may be a variety. 



o o Involucre 3.2-5 mm. long. 



+ Stem closely and minutely pubescent throughout. 



43. S. altissima L. Stem cinereous-puberulent, stout, 0.7-2 m. high ; leaves 

 thickish, lanceolate, subentire or more or less toothed, minutely pubescent or 

 scabrous above, short-pilose beneath, the middle ones 6-13 cm. long, 10-18 mm. 

 broad ; heads crowded in recurved racemes forming dense high broadly pyram- 

 idal panicles ; involucre 3.2-4.5 mm. long, its subherbaceous bracts linear. 

 {S. canadensis Man. ed. 6, in part, including var. scabra T. & G.) — Rich open 

 ground, Aroostook valley. Me.; Mass. and Vt. to Mich., Kan., and south w. 

 Aug.-Oct. 



Var. pr6cera (Ait.) Fernald. Stem and lower surface of the leaves more 

 loosely pubescent with distinct soft hairs ; branches of the panicle strongly 

 ascending, scarcely if at all recurved at tip. (>S^. procera Ait.; S. canadensis, 

 var. T. & G.) — A little known extreme, apparently best developed in the 

 L. Superior region. — In inflorescence simulating S. elongata Kutt. of the North- 

 west and of the lower St. Lawrence, which has glabrous or glabrate stems and 

 leaves, and less herbaceous involucre. 



+ + Stem glabrous throughout {or except in the inflorescence) . 



44. S. ser6tina Ait. Stem stout, 0.5-2.5 m. high, smooth, often glaucous; 

 leaves quite smooth both sides, lanceolate to oblanceolate, taper-pointed, very 

 sharply serrate, except the narrowed base, rough-ciliate ; the middle ones 7-16 

 cm. long, 1-3 cm. wide ; the ample panicle pubescent ; involucre 3.5-5 mm. long, 

 its bracts linear, subherbaceous ; rays 7-14, rather long. — Thickets, in rich soil, 

 N. B. to B. C., and southw. July-Sept. 



Var. gigantea (Ait.) Gray. Leaves glabrous above, slightly pubescent be- 

 neath, especially on the nerves; involucre 3.2-4 mm. long. — Low ground, 

 6. Que. to 111., and southw. 



2. Leaves broad-elliptic or -ovate. 



45. S. Drumm6ndii T. & G. Stem (3-9 dm. high) aiid lower surface of the 

 broadly ovate or oval someichat triple-ribbed leaves minutely velvety-pubescent, 

 some of the leaves almost entire ; racemes panicled ; bracts of the involucre 

 oblong, obtuse; rays 4 or 5. — Limestone cliffs and rocky woods, s. w. 111. and 

 Mo. to La. Sept., Oct. 



H_ ^_ H_ ^_ Heads in a compound corymb terminating the simple stem, not at all 



racemose ; leaves mostly with a strong midrib. 



-M- Leaves flat, noto-nerved. 



46. S. rigida L. Rough and somewhat hoary with a minute pubescence ; 

 stem stout, 0.3-1.5 m. high, very leafy ; leaves oval or oblong, copiously feather- 

 veined, thick and rigid, the basal 1-3 dm. long, petioled ; the upper closely ses- 

 sile by a broad base, slightly serrate, the uppermost entire ; corymb dense ; 

 heads more than SO-Jlowered; the involucre 6-8 mm. long ; rays 7-10. — Dry soil, 

 Mass. to Man., and southw. Aug.-Oct. 



47. S. ohioensis Riddell. Veiy smooth throughout; stem wand-like, slen- 

 der, leafy, 6-9 dm. high ; stem-leaves oblong-lanceolate, flat, entire, rough-mar- 

 gined, obscurely feather-veined, closely sessile, the upper only 3-4 cm. long ; 

 the lower and radical ones elongated, 3 dm. long, slightly serrate toward the 

 apex, tapering into long margined petioles ; heads numerous, on smooth pedicels, 

 lQ-20-flowered ; the involucre 4.5-6 mm. long ; rays 6 or 7. — Swamps and wet 

 prairies, Ont. and w. N. Y. to Ind. and Wise. Aug., Sept. 



