224 COMPOSITACEAE (COMPOSITE FAMILY) 



GG. Heads all alike, of both pistillate and perfect flowers; pappus bristles not 

 swollen at tip. — (Gk. gnaphalon = a lock of wool; referring to the heads.) 



GnaphaUum (cudweed) 



CC. Most of the leaves opposite. 



H. Pappus none or of capillary bristles; heads many-flowered; involucre bracts 



several to many. 



I. Receptacle depressed-globose, chaffy; akenes inclosed in involucre bracts. — 



(Gk. psilos = naked, carphos = a small dry body; probably because the 



ake^es are naked.) ' Psilocarphus 



n. Receptacle columnar, villous; akenes hardly inclosed in involucre bracts, 



U. — (Possibly from Gk. evaxos = easily broken.) " Evax 



HH. Pappus of stout plumose bristles; heads 2-flowered; involucre bracts 2. E. 



— (Origin undetermined.) Dimeresia howellii 



BB. Leaves broadly ovate, cordate at base, glabrous and green above, white-woolly 



beneath; pappus none. W. C. E. — (Gk. aden = a gland, kaulos = a stem; the 



stem is very glandular above.) Adenocaulon bicolor (silver-green) 



AA. Heads 3-10 cm. wide, radiate; basal leaves 1-2 dm. wide, 2-5 dm. long; leaves 



pubescent but not woolly; pappus bristles capillary, rough. W. — Medicinal plant. 



(The Latin name.) Inula heleniiun (elecampane) 



HELIANTHEAE (Sunflower Tribe). — Herbs. Leaves commonly oppo- 

 site at least below. Heads radiate or rayless; involucre not scarious; 

 receptacle chaffy. Ray flowers yellow or white or pinkish. Disk flowers 

 various in color. Anthers not tailed at base. Style branches of the perfect 

 flowers truncate or tipped with a hairy appendage. Pappus none or never 

 of capillary bristles. 



A. Heads radiate, i.e., with some ligulate outer flowers. 

 B. Rays yellow. 

 C. Disk flowers dark brown or purple. 

 D. Upper leaves mostly not dissected, or when some are dissected the plant not 

 glabrous; pappus of 2 to several teeth or awns. 

 E. Receptacle in fruit conical to columnar, akenes 4-angled, not winged; leaves 

 alternate, entire to pinnatifid. RTJDBECKIA (p. 226) 



EE. Receptacle in fruit flat or convex; akene flat or 4-angled, often somewhat 

 winged; leaves alternate or opposite, entire or merely dentate. 

 F. Annual; receptacle flat; akene somewhat 4-angled; not at all winged, 



HELIANTHUS (p. 227) 

 FF. Perennial; receptacle convex; akene flat, i or both edges somewhat 

 winged. E. — (Diminutive of Eelianthus, a related genus.) Helianthella 



DD. Upper leaves nearly all of 3 leaflets; plant glabrous throughout; pappus of 

 2 short teeth. W. E. — (Gk. koris = a bug, opsis = like; referring to the form 

 of the akene.) Coreopsis atkinsoniana (tickseed) 



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 inclosing 

 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. 227) 



JJ. Pappus a crown of 3-10 teeth, some of which may be awn-tipped; leaves 

 all alternate, mostly entire, never pinnately lobed. WYETHIA (p. 227) 



