T „vTT,r*1 SYNGENES1A 48T' 



B btpik^ata, L. Leaves bipinnate ; heads subradiate ; outer 

 Vs of the involucre scarcely as long as the inner. Beck, Bot. 



p. 207. 



BipnurXTX Bidens. Vulgo— Spanish Needles. 



« j annual. Stem 2 to 4 feet high, quadrangular, striate, smooth, branched. 

 2 to 4 or 5 inches long, and an inch and half to 3 inches wide, smoothish, 



6 ewhat delioid-ovatc in the outline, bipinnately dissected, the segments irregu- 

 larly lance-ovate, acute or obtuse, slightly mucronate, mostly cuneate and attenu- 

 al base, the common petiole 1 to 3 or 4 inches long, striate, smooth. Heads of 

 fl ers small, oblong, on long naked angular-sulcate terminal and axillary 



duncles ; involucre double, the leaflets lance-linear, connate at base,— the outer 

 nesabout 3, rather shorter and narrower than the inner ones, — inner ones scarcely 



i on <r as the head, brown, with a narrow scarious margin, and minutely pubes- 

 cent-cUiate at summit; rays about 3, obovate, small, yellow, with dark veins; 

 florets of the disk yellow. Ahcnes about 3 fourths of an inch long, subliaear, 

 angular and sulcate, somewhat scabrous with short erect hairs, and often marked 

 with rugose tawny spots ; pappus consisting of 3 or 4 retrorsely hispid axons about 

 as Ion" as the florets. Receptacle chaffy, the chaff lance-linear, shorter than the 

 akenes. 

 Uab. Gardens, and cultivated lots: common. Fl. August— Sept. Fr. Octo. 



Obs. All the foregoing species are noted for the mature akenes adhering, by 

 their barbed awns, to the clothing of those who go amongst them in autumn. The 

 two first mentioned abound in our swampy low grounds; and the two latter are 

 troublesome weeds about gardens, and cultivated lots. Two or three additional 

 species are enumerated in the U. States. 



Sub-Tribe 5. Helesiem. Heads never dioicous,— when heterogamous, with 

 pistillate or neutral florets in a single series in the circumference bearing ligulat© 

 corollas, the rest perfect. Anthers ecaudate. Akenes not beaked ; pa}>pus of many 

 chaffy scales. 



388. HELENIUM. L. JYutt. Gen. 684, 

 [Said to have been derived from Helen, the wife of IMenelaus.] 



Involucre many-leaved, the leaflets in a single series, connate at base. 

 Rays numerous, pistillate, cuneate, mostly 3-Iobed at apex. Akenes 

 siriatc-pilose ; pappus chaffy, acuminate, awned. Receptacle convex, 

 with chaffy bracts on the margin only. 



1. H. autumnale, L. Stem angular, sub-alate; leaves lanceolate, 

 serrate, decurrent ; disk globose ; rays spreading, or reflexed. Meek, 

 Bot. p. 301. Icoy, Bart. Am. \. tab. 26. 



Autumnal Helenium. Vulgo — False Sun-flower. Sneeze-weed. 



Whole plant of a palish cinereous-green. Root perennial. Stem 2 to 5 feet 

 high, corymbose-paniculate, angular, striate, minutely pubescent, yellowish, with 

 the angles green and slightly winged by the decurrence of the leaves; branches 

 angular and leafy. Leaves alternate, 2 to 4 inches long, and half an inch to an 

 inch wide, lanceolate, acuminate, irregularly serrate, narrowed at base, sessile, 

 minutely pubescent, and puncticulate under a lens. Heads of flowers middle- 

 •ized (an inch to an inch and half in diameter, including the rays), numerous; 

 peduncles 1 to 2 inches long, rather slender, thickened near the involucre, sulcate- 

 •triate, pubescent, terminal and axillary on the corymbose-paniculate branches 



