‘SILpHiuM. LXXV. COMPOSIT &. 336 
serted; receptacle naked; pappus capillary.—Shrubby plants, with 
alternate leaves and white flowers. 
B. HALIMIFOLIA. Groundsel Tree. 
Shrubby ; lvs. obovate, incisely dentate above, the highest ones lanceo- 
late ; panicle compound, leafy ; fascicles pedunculate.—This is almost the only 
arborescent plant of this order found in the Northern States. It is 6—12f high, 
growing on sea-coast and river alluvion. Every part is covered with white 
dust. The fertile heads growing upon separate plants are in large, loose, ter- 
minal panicles, and furnished with very long, slender pappus. Corollas white. 
Sept. The beauty of this shrub entitles it to cultivation. 
Trine 4. SENECIONIDEZ. 
Heads radiate or discoid. Branches of the style linear, hairy or hispid at 
the apex, which is either truncated or produced into a conical or elongated ap- 
pendage. Leaves opposite or alternate. 
Section 1. Heads radiate. 
25. ARNICA. 
Involucre of equal, lanceolate scales, 1 or 2 rowed; ray-flowers Q, 
disk §; receptacle flat, with scattered hairs; pappus single, rigid and 
serrulate.—% St. simple. Lvs. opposite. ls. yellow. 
A. MOLLIS. 
St. pubescent, erect; Jvs. pubescent, becoming nearly glabrous, thin, veiny, 
dentate, ovate-lanceolate and oblong; radical ones stalked, cauline sessile; 
Ads. few; invol. hairy, with acuminate scales; ach. hairy.—An alpine plant 
found in ravines on the White Mts., and also, according to Torrey g Gray, on 
the Mts. in Essex Co., N. Y. Stem 1—2f high, with several pairs of sessile 
leaves, and 1—5 yellow heads of middle size. Leaves 2—5 inches in length, 
the upper ones broad at the base, the lower tapering to a winged petiole, often 
acute but not acuminate. 
26. POLYMNIA. 
The name of one of the ancient Muses; why applied to this plant is not obvious. ; 
Involucre double, outer of 4 or 5 large, leafy scales, inner of 10 
leaflets, concave; ray-flowers pistillate, few; disk sterile; receptacle 
chaffy ; pappus none.—% Clammy herbs. Lvs. opposite. Fls. yellow. 
1. P. Canavensis. Leaf-cup. 
‘Viscid-villous; dvs. denticulate, petiolate, acuminate, lower pinnatifid, up- 
er 3-lobed or entire.—A coarse, broad-leaved, hairy-viscid plant, 3—5f high, 
‘Niagara Falls! Stem with opposite leaves and spreading branches. Flowers 
light-yellow, the rays short, surrounded by the concave leaflets of the double 
calyx in such a manner as to form a sort of cup, hence called leaf-cup. Leaves 
feather-veined, 3—8’ long, and nearly as wide, lobes deeply divided and acu- 
minate. Heads 2’ diam. June. 
2. P. uvepauia. Yellow Leaf-cup. 
Iws. opposite, 3-lobed, acute, decurrent into the petiole, lobes sinuate- 
angled; rays elongated.—In highland woods. Stem 3—6f high. Lower leaves 
very large. Flowers large, yellow, the rays much longer than the involucre. 
July.—Neither of these plants has been found in N. Eng., and they are rare in 
N. Y., but not uncommon in the Western States! 
27. SILPHIUM. 
Heads many-flowered ; ray-flowers numerous, in 2 or 3 rows, fer- 
tile, outer row ligulate ; disk flowers sterile ; involucre campanulate, 
seales in several series, leafy and spreading at summit; receptacle 
small, flat, chaffy ; pokents broad, flat, obeompressed, crowned with a 
t 
