composite. 93 
of the stylo 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. 
GENUS XVIII— B I D E N S. Linn. 
Antliodcs heterogenous and radiant, or homogamous and dis- 
coid, many-flowered. Periclinc 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. Florets of the disk 
perfect, regular, with a tubular corolla ; those of the ray in a 
single row, neuter, with a ligulate corolla, frequently absent. 
Aehcncs 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.— B I DENS CERNUA. Linn. 
Plate DCCLXIII. 
Reich. Ic. FI. Germ, et Helv. Vol. 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. Periclinc 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, dlscoidea. 
Anthodes discoid. 
Var. 3, radiata. 
Coreopsis Bidens, Linn. Sp. Plant, p. ll'Sl. 
Anthodes radiant, with ligulate neuter florets round the cir- 
cumference. 
