COMPOSITAE (COMPOSITE FAMILY) 797 



++ --* Leaves somewhat folded, entire, the lower slightly 3-nerved. 



48. S. RiddSllii Frank. Smooth and stout, 0.5-1 in. high, very leafy, the 

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

 ceolate, Ih'- riiitlim- i-l'inijitted (1-1. & dm. long), acute, partly clasping or sheath- 

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

 into a long keeled petiole ; heads very numerous, clustered, 20-30-flowered ; rays 

 7-9. \Vet grassy prairies, Ont. 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, aculish, rough-margined, 0.5-1.3 dm. 

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

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

 several, 20-30-flowered ; involucre 6-8 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 

 oppressed involucral bracts somewhat glutinous; receptacle fimbrillate ; 

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

 entire, sessile. 



* Leaves distinctly 3-5-ribbed ; heads 20-?>Q-floicered. 

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



50. S. graminif6lia (L.) Salisb. Stem 6-10 dm. high, glabrous; leavep 

 lance-linear, the primary ones 6-13 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 obleng. (Euthamia Nutt.; 8. 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. 



*- -i- Involucre 3-3.5 mm. long, the bracts with conspicuous green tips. 



51. S. polyce*phala Fernald. Similar to the preceding variety; leaves 

 elongate, thin, pubertilous ; branches of the corymb very hirtellous. their 

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

 somewhat puberulent bracts with closely oppressed deltoid green tips. Apparently 

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



* * Leaves l-ribbed or obscurely 3-nerved; heads \2-2Q(rarely 22)-floicered. 

 *- 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-tipped, \-ribbed. punctate, commonly 

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

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

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

 bracts with slightly green acutish tips. (S. tennifolia Pursh, in part.) Sandy 

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



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

 w- Involucre 3-4 mm. long. 



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

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

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

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



