396 Compositaceae 
EE. Receptacle in fruit flat or convex; akene flat or 4-angled, often some- 
what winged; leaves alternate or opposite, entire or merely dentate. 
F. Annual; receptacle flat; akene somewhat 4-angled, not at all winged. 
HELIANTHUS (p. 400) 
FF. Perennial; receptacle convex; akene flat, | or both edges somewhat 
winged. HELIANTHELLA (p. 401) 
DD. Upper leaves nearly all of 3 leaflets; plant glabrous thruout; pappus of 
2 short teeth. Coreopsis (p. 401) 
CC. Disk flowers yellow. 
G. Pappus either none or else not of retrorsely-barbed awns. 
H. Heads 2.5 cm. or more wide; involucre-bracts flat or nearly so, not 
enclosing a ray akene; leaves often wider than lanceolate. 
I. Most of the leaves basal; ray-flowers pistillate, fertile. 
J. Pappus none; leaves opposite or alternate, in some species pinnately 
lobed to pinnatifid. - BALSAMORHIZA (p. 399) 
JJ. Pappus a crown or of 3—10 teeth, some of which may be awn- 
tipped; leaves all alternate, mostly entire, never pinnately lobed. 
WYETHIA (p. 400) 
II. Most of the leaves on the stem; ray-flowers neutral; pappus of 2—6 
deciduous scales or awns. HELIANTHUS (p. 400) 
HH. Heads less than 2.5 cm. wide; involucre-bracts boat-shaped, more or 
less enclosing an outer or ray akene; leaves lanceolate or narrower (except 
Lagophylla.) 
K. Akenes flattened laterally, Weerwat right angles to the involucre; in- 
volucre-bracts keeled on the back; plants. mostly viscid-glandular; pappus 
none except in M. madioides, of 5—-8 scales. MapI< (p. 402) 
KK. Akenes not flattened laterally; involucre-bracts rounded or flattish 
on the back. 
L. Pappus none. : 
- M. Leaves of the stem pinatifid; leaves of the branches and fascicles 
entire, spinulose-tipped; involucre-bracts  spinulose-tipped;__ disk- 
flowers 10 or more; ray-flowers 10 or more; most of the leaves 
alternate. HEMIZONIA (p. 403) 
MM. Leaves all entire, not spinulose-tipped; involucre-bracts not 
spinulose-tipped; disk-flowers |—6; ray-flowers 46. 
N. Disk flowers 1—2, fertile; akenes slightly hairy; plant 
2.5—20 cm. high; most of the leaves opposite, 2.5 or less long. 
HEMIZONELLA (p. 403) 
NN. __ Disk-flowers 5—6, sterile; akenes smooth; plant 15—75 
cm. high; most of the leaves alternate, 5 cm. or less long. 
LAGOPHYLLA (p. 403) 
LL. Pappus present at least on the disk akenes, of 712 scales which 
are often awn-tipped. 
O. Upper leaves spinulose- or gland-tipped; pappus of 7—12 
scales, in | whorl, often awn-tipped, its scale portion 3 mm. or less 
HEMIZONIA (p. 403) 
OO. Leaves neither spinulose- nor gland-tipped; pappus of about 
10 scales, in 2 whorls, not awn-tipped, inner whorl about 6 mm. 
long. ACHYRACHAENA (p. 404) 
GG. Pappus of 2—6 stout retrorsely-barbed awns; heads 0.8—10 cm. wide. 
BIDENS (p. 401) 
BB. Rays white or pink. 
ans 
