192 DICOTYLEDONOUS. 



Genus L. BIDENS. 



Involucre double, the o-iter unequal ^ ray florets neutral 

 when present, frequently wanting; those of the disk perfect. 

 Receptacle flat, chaffy. Pappus consisting of 4 retrorsely 

 scabrous awns. Seed quadrangular. 



1. B, Chrysanthemoides. Stem glabrous below ; somewhat pubescent 

 towards the summit, with opposite branches. Leaves sessile, opposite, ob- 

 long-lanceolate, serrate, glabrous, somewhat connate ; involucre double, the 

 exterior one consisting of about 8 unequal foliaceous leaves ; the interior of 

 about the same number of equal, membranaceous leaves ; ray florets lanceo- 

 late, 8. (Seeri c.»mpre^sed, oblong; pappus consisting of 2 awns which are 

 distinct, and 2 others very minute : receptacle convex. 



Yellow. % Oct. — Nov. In wet cultivated lands- 2-3 ft. 



2. B. Co.xNATA. Stem glabrous, with opposite branches. Leaves opposite 

 lanceolate, toothed, glabrous, attenuate, at the base, the lower ones ternate, 

 the upper ones simple, all sessile. Flowers solitary, on opposite peduncles, 

 the exterior involucre foliaceous, the interior chaffy ; ray florets none. 



Yellow. % July— Oct. Middle CaroUna and Georgia. 2-3 feet. 



3. B. PiLOSA. Stem pubescent, branching, lower leaves dentate, pubescent. 

 Flowers solitary, on opposite and terminal peduncles ; exterior involucre foli- 

 aceous, the interior chaffy ; ray florets none. 



Yellow. %. July— Oct. Common. 2-3 feet. 



4. B. Fkondosa. Stem slightly pubescent, branching. Leaves lanceolate, 

 the lower ones pinnate, the upper ternate and simple, slightly pubescent. 

 Flowers solitary, on opposite and terminal peduncles ; exterior involucre with 

 unequal, ciliate leaves ; the exterior chaffy ; ray florets none. 



Yellow. % June — Sept. Damp soils, common. 



5. B. BiPiNKATA. Stem glabrous, obtusely angled, with opposite branches. 

 Leaves opposite, decussate, bipinnate ; leaflets lanceolate, pinnaiifid, slightly 

 pubescent along the margin. Flowers on long, usually terminal peduncles; 

 exterior involucre w-iih linear-lanceolate leaves; interior leaves ciliate to- 

 wards the summit. &ed slightly angled. 



Yellow. % July— Oci. Common. 2-4 feet. 



Genus LI. COREOPSIS. 



Inmlucre double, each many leaved, the exterior equal, the 

 inner one sub-coriaceous, and colored. Receptacle chaffy, 

 with fiat scales. Seeds compressed, emarginate. Pappus 

 consisting of 'Z awns ; ray florets neutral ; those of the disk 

 perfect. 



(a) Leaves opposite, entire. 



1. C. Lanceolata. Stem procumbent, glabrous towards the summit, 

 branching at the base. I.eat;es sessile, entire, Iniear-lanceolate, ciliate towards 

 the base. Flowers solitary and terminal, on long, naked branches; involu- 

 cre with the leaves about equal in both series ; ray florets toothed at the sum- 

 mit, about 8. Seed compressed, winged; pappus 2 subulate, hairy awns ; 

 chaff narrow. 



Yellow. % April— May. Damp soils. 1-2 feet. 



2. C Crassifolia. Stem pubescent, striate, branched at the base. Leaves 

 opposite, oblong, the lower ones alternate at the base, hirsute. Flowers ter- 

 minal ; involucre glabrous ; ray florets toothed, about 8. 



Yellow. % June — July. Pine barrens, common. 1-2 feet. 



3. C. Arguta. Stem glabrous. Leaves lanceolate-ovate, acuminate, ser- 



