COMPOSITE. 93 



of the style in the fertile flowers linear, convex externally, flat 

 internally, hairy or tufted at the apex. Achenes generally com- 

 pressed or prismatic. Pappus none, or crown-like or of awns. 



GBNVS Xrill.—B I D E N S. Linn. 



Anthodes heterogamous and radiant, or homogamous and dis- 

 coid, many-flowered. Pericline hemispherical or campanulate, of 

 2 rows of phyllaries, the exterior ones herbaceous and foliaceous, 

 generally reflexed, the interior row scarious. Clinanth slightly 

 convex, pitted, furnished with scarious scales. Elorets of the disk 

 perfect, regular, with a tubular corolla ; those of the ray in a 

 single row, neuter, mth a ligulate corolla, frequently absent. 

 Achenes generally compressed, with 1 or 5 awns at the apex, 

 which are the only representatives of the hairs of the pappus. 



Annual or perennial herbs with opposite leaves, and generally 

 with terminal and axillary anthodes of yellow florets. 



The name of this genus of plants comes from the words bis, double, and dens, a 

 tooth, in allusion to the awns of the seeds. 



SPECIES I.— BIDENS CERNUA. Linn. 



Plate DCCLXIII. 



Reich. Ic. Fl. Germ, et Helv. Yol. XVI. Tab. CMXLI. Fig. 2. 

 Billot, Fl. Gall, et Germ. Exsicc. No. 2087. 



Stem slightly hairy. Leaves glabrous, strapshaped-elliptical, 

 coarsely serrate ; those near the middle of the stem sessile and 

 sub-connate at the base. Anthodes drooping, solitary at the ex- 

 tremity of the stem and branches. Pericline broader than long ; 

 outer phyllaries foliaceous, unequal, reflexed or spreading, longer 

 than the inner ones, rough at the edges ; inner phyllaries broadly 

 oval, scarious, about as long as the florets. Achenes much com- 

 pressed, enlarged upwards, sessile, with 4 ribs, all (rarely only 3) 

 of which terminate in awns, which, as well as the ribs, are armed 

 with reflexed prickles. 



Var. a, discoidea. 

 Anthodes discoid. 



Var. /3, radiata. 

 Coreopsis Bidens, Linn. Sp. Plant, p. 1281. 



Anthodes radiant, with ligulate neuter florets round the cir- 

 cumference. 



