144 FAM. 173. 



heads mostly in spikes or racemes; — leaves alternate; heads 

 rose-purple or white. Summer and Fall. 



Laciniaria (Liatris), Button Snakeroot or Blazing Star 



L. spicata. Leaves numerous, linear, smooth; spikes long, cylindrical, often 

 dense; involucres rounded at the base, sessile, the bracts glabrous or nearly 

 so, copiously punctate; heads sessile, 8-12 flowered, purple. Moist soil. 



L. Chapmanii. Leaves narrowly linear, numerous on the lower, much reduced 

 and sessile on the upper part of the rigid stem; spikes dense, plumose when 

 mature, heads mostly 3-flowered; bracts ovate to lanceolate. Sand-hills. 

 10. Erect herbs or shrubby plants; — leaves alternate, opposite, or whorl- 

 ed; heads in corymbs or panicles; receptacle flat; involucres nar- 

 row with scarious or membranous bracts; anthers appendaged 

 at the apex; flowers mostly white. Spring to Winter, - Eupatorium 



a. Leaves compound with narrow-linear segments, ----- b 



a. Leaves simple, at most toothed or incised, ______ q 



b. Leaves very numerous, with narrow-linear segments; — plant 



fennel-scented; heads 3-5 flowered, in panicles; bracts lan- 

 ceolate with scarious margins. Old fields. 



E. capillifolium (foeniculaceum), Dog-fennel 



b. Leaves numerous, compound on the lower part of the stem to 

 entire on the upper part, segments linear; — heads 5-flowered, 

 in panicles; bracts narrowly lanceolate. Dry soil. 



E. compositifolium (coronopifolium) 



c. Leaves petioled, --------« - d 



c. Leaves chiefly sessile, ---------e 



d. Heads 5-flowered, ------- E. mikanioides 



d. Heads 10-30 flowered, ------ E. aromaticum 



e. Leaves linear to lanceolate, -___-__-f 



e. Leaves lanceolate to ovate or oblong, ------ g 



f. Smaller leaves clustered in the axils of the larger, - E. hyssopifolium 



f. No smaller leaves present, ------ E. leucolepis 



g. Inner bracts of involucre with white tips, - - - - E. album 



g. Inner bracts of involucre petaloid, E. petaloidum 



g. All bracts of involucre alike, _______-h 



h. Bracts of involucre with scarious margins and apex, - E. cuneifolium 



h. Bracts of involucre canescent, ____----i 



i. Branches of inflorescence alternate, E. verbenaefolium 



i. Branches of inflorescence opposite, - - - - - E. scabridum 



10. Resembling Eupatorium, but receptacle conical or hemispherical. 



Conoclinum 

 E. (C.) caelestinum, Mist-Flower. Cultivated as a bedding-plant with small 

 blue or violet flowers in cymose heads; leaves ovate to deltoid-ovate. Shaded 

 ground. Summer. 

 10. Low herbs with simple leaves; small heads of flowers in corymbs; 

 bracts of involucre in 2-3 rows; receptacle flat or nearly so; 

 pappus simple of 5 or more scales. Cultivated for bedding. Summer. 



Ageratum 

 A. conyzoides. Stems often branched; leaves ovate to deltoid, crenate-serrate 



on short petioles, pubescent; flowers blue, white or rose. 

 A. (Conoclinum) Lasseauxii. Leaves lanceolate to elliptic; flowers rose. 

 10. Herbaceous twining vines; — leaves opposite, slender-petiole d, cor- 



