


Compositaceae 409 
CHRYSANTHEMUM CHRYSANTHEMUM 
Herbs, our perennial. Leaves alternate, incised or dissected. Heads radiate, large; 
involucre hemispheric or flatter; its bracts oppressed, imbricated, the outer shorter; recep- 
tacle flat to hemispheric, naked. Ray-flowers pistillate, fertile, white. Disk-flowers per- 
fect, yellow, 2-winged or terete, 4—5-toothed. Akenes 5] 0-ribbed, terete, or the ray- 
akenes 3-angled. Pappus none or a toothed crown. (Gk. chrysos=gold, anthos—=a 
flower; some species even have yellow rays.) 
A. Heads 1—2 cm. wide, many, corymbose; rays |0-——20, about twice as long as wide; 
pappus a toothed crown. E. C. parthenium Pers. (Fever-few) 
AA. Heads 2.5—5 cm. wide, few, terminal; rays 2030, 4 or more times as long 
as wide; pappus none. W. (C. leucanthemum subpinnatifidum.) 
C. leucanthemum L. (Ox-eye Daisy) 
SOLIVA 
Herbs, ours 5—10 cm. high. Leaves alternate, pinnately dissected, petioled. Heads 
rayless, sessile in the leaf-axils or stem-forks, small, with 2 kinds of flowers; involucre- 
bracts 512, nearly equal, in |—2 series; receptacle flat, naked. Outer flowers many, 
apetalous, pistillate, fertile. Central flowers perfect, mostly sterile; corolla yellowish- 
green, 2—6-lobed. Akenes obcompressed, 2-winged or -margined, the margins each spine- 
tipped at apex; style persistent, spine-like. Pappus none. (Perhaps L. solus—alone, 
vagus—wandering.) U. S. sessilis R. & P. ‘ise 
COTULA 
Herbs, low. Leaves alternate, lobed or dissected. Heads rayless, many-flowered, 
peduncled, with 2 kinds of flowers; involucre hemispheric; its bracts greenish, in about 2 
series; receptacle naked, flattish. Outer flowers pistillate, fertile, in 1—-3 rows, apetal- 
ous; style deciduous. Inner flowers 4-toothed, yellow, perfect, fertile. Akenes pedicelled 
at maturity, obcompressed. Pappus none or a mere ring. (Gk. kotula—a small cup, 
referring to the hollow at the base of the clasping leaves. ) 
A. Herbage glabrous or very nearly so. W. 
C. coronopifolia L. (Salt-marsh Butter-head) 
AA.  Herbage pubescent. C. australis Hook. 
TANACETUM TANSY 
Herbs, perennial, aromatic. Leaves alternate, entire to dissected. Heads rayless, 
many-flowered, solitary or corymbose, with | or 2 kinds of flowers; involucre-bracts imbri- 
cated in | to few series; receptacle naked. Outer flowers when different pistillate, fertile, 
oblique or imperfectly ligulate. Inner flowers perfect, fertile, 3—5-toothed, regular. 
Akene 5-ribbed or 3—5-angled, with wide truncate tip; style deciduous. Pappus none or 
crown-like. (Said to be from Gk. athanatos=immortal; referring to the durable flow- 
ers. 
A. Leaves 2—-5-lobed or parted, but some of the leaves may be entire. 
B. Leaf-lobes linear. E. TT. capitatum T. & G. 
BB. Leaf-lobes not linear or none of the leaves lobed. E. (7. canum.) 
T. nuttallii T. & G. 
AA. Leaves pinnately-parted or -dissected into many segments. 
C. Herbage quite pubescent. 
D. Claibrac silky with white hairs; heads many, 6—8 mm. wide. E. 
T. potentilloides Gray 
