oa 
he 
Compositaceae 379 
DD. Involucre-bracts obtuse or merely acutish, not subulate; leaves often 
sharply and much serrate. 
F. Leaves entire or nearly so; heads 4—6 mm. high; leaves thick, firm (as 
in Willows). 
G. Branches of the panicle not 1-sided, not recurved; involucre-bracts 
acutish, thin; leaf-margin mostly scabrous-ciliate. W. E. 
S. tolmieana Gray 
GG. Branches of the panicle I-sided, recurved; involucre-bracts obtuse, 
thick; leaf-margin not ciliate. E. 
; S. missouriensis Nutt. 
FF. Leaves sharply and distinctly serrate; heads 5-7 mm. high; leaves 
thin (as in Dandelion) ; raceme 1-sided, recurved. 
H. Leaves smooth on both sides. E. 
S. serotina Ait. 
HH. Leaves harshly rough on both sides. W. E. 
S. serotina salebrosa Pip. 
CC. Plant puberulent to pubescent; leaves entire except the lower, obtuse or apic- 
ulate; heads 6—8 mm. long; involucre-bracts obtuse. U. F. 
S. californica Nutt. 
BB. Branches of the panicle not raceme-like. 
I. Involucre-bracts acute or acuminate. W.C.E. (S. hesperia. ) 
S. corymbosa Nutt. 
II. Involucre-bracts obtuse. 
J. Leaves mostly obovate or spatulate and entire. E. 
S. nana Nutt. 
JJ. Leaves oblanceolate or oblong to linear, distinctly serrate or crenate at 
least near the tip. 
K. Panicle raceme-like, loose. W. 
S. purshii Port. 
KK. Panicle branched, dense. W. (S. confertifolia.) 
S. glutinosa Nutt. 
AA. Rays more numerous than the disk-flowers; receptacle somewhat fringed; inflor- 
escence flat-topped; leaves linear, entire, smooth, 3-veined. W. E. (Euthamia 
occidentalis. ) 
S. occidentalis T. & G. 
APLOPAPPUS (Haplopappus) 
Herbs or shrubs but mostly herbs with woody base, perennial (ours), low, often 
viscid, often hairy. Leaves alternate, rigid, entire or dentate. Head radiate or rayless, 
8—20 mm. high (ours), yellow, few or many-flowered, all alike, either terminal on the 
stem or branches, or else on axillary peduncles, rarely sessile; involucre hemispheric or 
widely campanulate; bracts in 2 to many series, 0—1-veined; receptacle flat or nearly 
so, pitted. Ray-flowers 0—25: corolla yellow. Disk-flowers perfect: corolla 5-toothed, 
yellow. Akene glabrous or hairy. Pappus of bristles; bristles many, white or brownish 
or reddish, unequal, mostly in more than | whorl, simple to barbellate or sometimes nearly 
plumose. (Gk. aploos—simple, pappos=pappus; the pappus is not plumose.) 
A. Heads rayless. 
B. Leaves with spinulose-tipped teeth. 
C. Akenes densely hairy; pappus white. SIDERANTHAE (p. 380) 
CC. Akenes glabrous, smooth; pappus brownish. PYRROCOMAE -(p. 380) 
BB. Leaves without spinulose-tipped teeth; akene pubescent. 
MacroNneEMAE (p. 381) 
