



Compositaceae 407 
ACTINELLA 
Low, perennial (ours). Leaves alternate, |—2-ternately parted (ours) ; lobes nar- 
row. Heads radiate’ (ours), peduncled, many-flowered; involucre-bracis in 2 or more 
series, often rigid, the outer sometimes united; receptacle conical to convex. Ray-flowers 
vellow, 4—10 mm. long, 3-toothed. Disk-flowers yellow. Akenes turbinate, 5—10- 
ribbed, villous or pubescent. Pappus-scales 512, thin, aristate, acuminate (ours). E. 
(Diminutive of Gk. aktis—=a ray; probably because the rays are short.) 
A. richardsoni Nutt. 
HELENIUM SNEEZE-WEED 
Leaves alternate, simple. Heads radiate (ours), many-flowered, peduncled;  in- 
volucre-bracts linear to subulate, herbaceous, spreading or reflexed, in 2 series; receptacle 
globose or hemispheric. Ray-flowers yellow, 3—5-toothed. Disk-flowers yellow, 4—5- 
toothed; teeth obtuse, glandular-pubescent. Akenes turbinate, 8—10-ribbed, hairy on 
the ribs. Pappus-scales 56, thin, scarious, acuminate or awn-pointed. (Said to be in 
honor of Helen of Troy, who used it cosmetically.) 
A. Leaf-blades not decurrent on the stem. E. (Dugaldia hoopesii.) 
H. hoopesii Gray 
AA. Leaf-blades decurrent on the stem. 
B. Leaves dentate; heads several to many. W.C. E. (H. autumnale grandiflorum.) 
H. autumnale L. 
BB. Leaves entire, head 1. U. 
H. bigelovii Gray 
GAILLARDIA 
Erect, ours pubescent with jointed hairs. Leaves alternate, in ours entire to sinuate- 
pinnatifid. Heads radiate (ours), many-flowered, large, terminal, peduacied; involucre- 
bracts in 2—3 series, hirsute; receptacle convex to globose, setaceous-chaffy. Ray-flowers 
yellow, 3-toothed. Disk-flowers yellow or brown, 5-toothed; teeth with jointed hairs. 
Akenes villous, turbinate, 5-ribbed. Pappus-scales 5—-10, hyaline, scarious, |-veined, 
-slender-awned (ours). (Honor of Gaillard de Merentonneau, a French botanist.) W. E. 
G. aristata Pursh 
ANTHEMEAE. (SacEBRUSH TRIBE)—Herbs or shrubs. Heads rayless or 
radiate; involucre-bracts imbricated, not foliaceous, rarely herbaceous, usually dry and 
scarious; receptacle naked or somewhat chaffy. Anthers not tailed at base.  Style- 
branches of the perfect flowers truncate, sometimes obscurely conic-tipped. Akenes usually 
small and short. Pappus none or chaffy or scale-like or crown-like. 
A. Herbs. 
B. Rays present. 
C. Rays 4—6, 4—6 mm. long; receptacle chafty. ACHILLEA (p. 408) 
CC. Rays 10 or more, 10 mm. or more long. | 
D. Receptacle chaffy at least toward its tp. ANTHEMIS (p. 408) 
DE. Receptacle naked or merely hairy. 
E. Leaf-segments terete or nearly so; receptacle conic. 
MatTRrIcaRIA (p. 408) 
EE. Leaf-segments plainly flat; receptacle flat to hemispheric. 
CHRYSANTHEMUM (p. 409) 
Bie aR ne. 
. aha caste in the leaf-axils or stem-forks. SOLIVA (p. 409) 
