COMPOSITAE (COMPOSITE FAMILY) 797 



•«. -M. Leaves somewhat folded, entire, the loioer slightly Z-nerved. 



48. S. Riddellii Frank. Smooth and stout, 0.5-1 m. high, very leafy, the 

 branches of the dense corymb and pedicels rough-pubescent ; leaves linear-lan- 

 ceolate, the cauline elongated (1-1.5 dm. long), acute, partly clasping or sheath- 

 ing, mostly recurved, the lowest elongated-lanceolate (3-5 dm. lon^) and tapering 

 into a long keeled petiole ; heads very numerous, clustered, 20-:]()-tlo\vered ; rays 



7_9. Wet grassy prairies, Out. to Minn, and Mo.; Ft. Monroe, Va. Aug., 



Sept. — Heads larger than in the preceding. 



49. S. Houghtbnii T. & G. Smooth ; stem rather low and slender, 3-6 dm. 

 high; leaves scattered, linear-lanceolate, acutish, rough-margined, 0.5-1.3 dm. 

 long, 5-10 mm. wide, tapering into a narrowed slightly clasi)ing base, 1-nerved, 

 or the lower .3-nerved and with margined petioles; veins obscure; heads few or 

 several, 20-30-flowered ; involucre 0-8 mm. long, with obtuse bracts ; rays 7-9. 

 — Swamps, north shores of Lakes Michigan and Huron; Genesee Co., N. Y. 

 July, Aug. 



§2. EUTHAMIA Nutt. Corymbosely much branched; heads small, sessile or 

 subsessile, in little clusters crowded in flat-topped corymbs; the closely 

 appressed involucral bracts somewhat glutinous; receptacle fimbrillate; 

 rays 6-20, short, more numerous than the disk-flowers; leaves narrow, 

 entire, sessile. 



* Leaves distinctly S-6-ribbed; heads 20-?j0-flowered. 

 +- Involucre 4-5 mm. long, the bracts usually without conspicuous tips. 



50. S. graminif51ia (L.) Salisb. Stem 5-10 dm. high, glabrous; leave? 

 lance-linear, the primary ones 5-13 cm. long, 4-9 mm. broad, glabrous except 

 for the scabrous margins and the minutely pubescent nerves beneath ; branches 

 of the inflorescence glabrous or at most minutely serrulate on the angles ; leafy 

 bracts of the inflorescence ascending ; heads obovoid-cylindric, sessile, in dense 

 corymbed glomerules ; involucral bracts straw-color or yellowish-green, their 

 tips rarely darker, the outermost ovate or oblong. (Euthamia Nutt.; S. lanceo- 

 lata Man. ed. 6, and perhaps L.) — Moist soil, e. Que. to Sask., s. to N. J., 111., 

 Mo., and along the mts. to N. C. Aug.-Oct. 



Var, Nuttallii (Greene) Fernald. Leaves more pubescent ; branches of the 

 inflorescence hirtellous. — N. S. to Mich, and Ala. 



4- s- Involucre 3-3.5 mm. long, the bracts with conspicuous green tips. 



51. S. polyc6phala Fernald. Similar to the preceding variety; leaves 

 elongate, thin, puberulous ; branches of the corymb very hirtellous, their 

 small bracts wide-spreading or deflexed; involucre turbinate, very small, its 

 somewhat puberulent bracts with closely appressed deltoid green i(ps.— Apparently 

 local, s. N. J. and e. Pa. Aug., Sept. • 



* * Leaves l-ribbed or obscurely S-nerved ; heads l2-20(rarely 22)-flower€d. 

 4- Leaves almost acicular, the middle cauline 1-1.5 mm. wide. 



52. S minor (Michx.) Fernald. Very slender, 4-8 dm. high, the glabrous 

 stem freely fastigiate-branched above the middle; leaves extremely slender, 

 the primary ones 3-5 cm. long, acerose-ti]iped, \-ribbed, punctate, commonly 

 subtending axillary fascicles as do many of the rameal ones ; heads mostly short- 

 pediceled', in numerous small corymbs ; involucre nearly cylindric, acute at base, 

 3-4 mm. long, 1-1.5 mm. thick, its firm appressed glutinous straw-colored 

 bracts with slightly green acntish tips. (^S. tenuifolia Pursh, in part.) — bandy 

 soil, near the coast, Va. to Fla. and Ala. Sept., Oct. 



4- ^ Leaves flat, broader, 2-6 mm. wide. 



++ Involucre 3-4 mm. long. 



53 S tenuifblia Pursh. Rather slender, 3-9 dm. high, the glabrous stem 



freely fastigiate-branclied above the middle ; leaves linear or linear-lanceolate, 



soon spreading or reflexed ; the primary oms 4-7 cm. long. 2-4 mm. broad, 



taper-pointed, l-ribhed, often obscurely 2-nerved, minutely punctate, usually 



