236 COMPOSITZ. (COMPOSITE FAMILY.) 
involucre oblong-linear ; rays wedge-shaped, palmately 3-lobed ; ovary wingless, 
with hispid margins. — River-banks, South Carolina and Georgia. September, — 
— Stem 2°-3° high. 
+ + + Rays purple or rose-color. 
16. C. nudata, Nutt. Smooth; stem slender, forking above ; leaves al- 
ternate, distant, terete, and rush-like ; rays bright purple, 3-toothed ; achenia with 
lacerated wings, 2-awned. — ERARA ponds; Florida and Georgia, near the 
coast. April— Stem 29 high. Lowest leaves 1° long. Rays 1' long. 
17. C. rosea, Nutt. Smooth; stem low, branching ; leaves opposite, lin- 
ear; heads small; rays slightly 3-toothed ; achenia wingless, unawned. — 
Swamps, Georgia, Nuttall, and northward. July and August. — Stem 8' -12! 
high. Rays rose-color. 
18. C. GEmleri, Ell Leaves broad-lanceolate, sessile, acute at each end, 
entire; peduncles axillary and terminal, dichotomously corymbose. — , 
near the junction of the Broad and Saluda Rivers by Mr. Œmler. Elliott, — 
Stem 29-39 high, angular, smooth. Leaves connate by a small membrane. 
Heads small. Rays about 8, entire. Achenia wedge-shaped, slightly 2-toothed 
and margined. (*) 
51. COSMOS, Cav. 
Scales of the involucre more or less united. Achenia terete or 4-angled, nar- 
rowed or beaked at the apex, and crowned with 2—4 downwardly barbed 9 2. |! 
hispid deciduous awns. Otherwise like Coreopsis. — Leaves opposite, p : 
divided. Disk yellow. Rays purplish. 
1. C. eaudatus, Kunth. Smooth; leaves bipinnately divided, with ‘the 
divisions lanceolate and entire; aghenia ( Jong) tapering into a very long 
beak, 2-awned ; rays short, 3-cl t, rose-color. — Key West, Florida. 
52. BIDENS, L. BEGGAR-TICKS. 
Chiefly like Coreopsis ; but the exterior involucre often long and taie 
the achenia compressed, or 3 - 4-angled, (not narrowed at the apex,) and i 
with 2—4 persistent downwardly barbed or hispid awns. — Leaves serra, 
pinnately divided, opposite. Rays yellow or white, often wanting. 
ellow. 
T * Achenia flattened, narrowly wedge-shaped. 
1. B. frondosa, L. Stem tall, branched ; leaves thin, long-petioled, Pit 
nately 3 - 5-divided ; the divisions ovate or Gvatelésinenleen, acuminate, sharply 
serrate; heads discoid; exterior scales of the involucre large, leafy ; achenis 
 2-awned. — Low ground, Florida and northward. July- Sept. O— 
29-5 high. Margins of the achenia upwardly ciliate. ure 
2. B. connata, Muhl. Stem low, branched; leaves oblong ance 
acuminate, coarsely serrate, tapering and connate at thie base, the lowest A 
3-parted ; heads discoid ; exterior involucre ‘leafy ; achenia 2- ie 
; downwardly hispid margins. — Western. districts. Mrd and westward ` 
. damp soil. T pt. ea cue ioe 
