COMPOSIT&. (COMPOSITE FAMILY.) 219 
29. PTEROCAULON, El. 
Heads and flowers chiefly as in Pluchea. Seales of the involucre lanceolate, 
imbricated in several rows, caducous. Receptacle minutely hairy. Achenia . 
angled, pubescent. Pappus of numerous equal capillary bristles, longer than 
the involucre. — Perennial herbs. Leaves lanceolate, densely tomentose and 
hoary beneath, the margins broadly decurrent on the stem. Heads compactly 
spiked. 
1. P. pycnostachyum, Ell. Stem rarely branched, 1°-2° high ; leaves 
wavy, smooth above ; spike thick, woolly ; flowers white. — Damp pine barrens, 
Florida to North Carolina. June and July. 
Trise IV. SENECIONIDEUE. Heads discoid or radiate: branches of the 
style, in the perfect flowers, linear, convex externally, hairy or brush-shaped at the 
apex, and truncate, or produced into a conical or hispid appendage ; the stigmatic 
lines terminating at the appendage, not confluent. 
30. POLYMNIA, L. 
Heads many-flowered ; the rays pistillate, in a single row; those of the disk 
tubular, 5-toothed, sterile. Scales of the involucre in two rows ; the outer leafy, 
spreading ; the inner smaller, membranaceous, clasping the obovoid fertile ache- 
nia, Receptacle chaffy. Pappus none.— Coarse branching perennial herbs, — 
with angular or lobed leaves, and heads of yellow flowers in corymbose panicles. 
1. P. Canadensis, L. Viscid-pubescent ; lowest leaves opposite, peti- 
oled, pinnatifid ; the upper alternate, angled or lobed ; outer scales of the invo- 
luere acuminate, hairy and viscid ; rays shorter than the involucre. — Mountains 
of North Carolina. rhe and August. — Stem 2°-5° high. Heads small. 
Rays pale yellow. 
2. P. Uvedalia, L. Stem smooth, or rough-pubescent; leaves broadly 
ovate, 3 — 5-lobed, coarsely toothed, rough above, pubescent beneath, abruptly 
Contracted into a sinuate-winged petiole ; outer scales of the involucre ciliate, 
obtuse ; rays much longer than the involucre. — Rich soil, Florida, and north- 
ward. July and August. — Stem 39 — 6? high. Rays bright yellow. 
31. CHRYSOGONUM, L. 
Heads many-flowered ; the rays 5, pistillate. Disk-flowers tubular, racial 2 
Sterile. Scales of the involucre in 2 rows; the exterior oblong, leafy ; the inte- 
rior roundish, clasping the oval Seaniptooned 4-angled fertile achenia. Receptacle 
flat, chaffy, Pappus a slightly lobed cup-shaped crown, divided on the inside to 
the base. — A low hairy stoloniferous perennial herb, with oval or spatulate- 
Opposite crenate leaves, and single heads of yellow flowers borne ona 
long peduncle, Me 
L c.  Virginianum, L.— Dry open std ada to North: Cuni 
February — April. — Plant at first simple, producing from a tuft of radical leave 
ting educit hend, fear inis and bacing 
