44 PITTONIA. 
Gray’s variety latifolium of that species. It is also the 
S. levigatum of Elliott, by the description, but can not be 
that of Pursh. The species is well represented in Mr. Ruth’s 
n. 777, from near Knoxville, Tennessee, of the collection of 
1898. 
SILPHIUM COLLINUM. Stem terete, stoutish, striate, 3 to 6 
feet high, glabrous, glaucescent, sparsely leafy, all the leaves 
alternate, petiolate, the petioles about as long as the blades; 
these of broadly ovate outline, commonly cordate or sub- 
cordate, angulate-lobed, the lobes entire or toothed: heads in 
an ample panicle, small; outer bracts of involucre ovate, the 
inner oblong-ovate, all obtuse, glabrous, only the margins 
scabrous-ciliolate: rays about 5, little more than 4 inch long: 
achenes puberulent, strongly obcordate, the wings so ending 
as to form a narrow and deep notch; awns not manifest, 
apparently wanting. 
Mountainsof eastern Tennessee to those of western Georgia ; 
not rare in collections, but mistaken for a form of S. com- 
positum, which is a plant of the lowlands of the southern 
seaboard, of half the size of the present species, with leafless 
and scapiform stem, the foliage appearing as if ternately 
compound (whence the name compositum). 
SILPHIUM Simpson. Stem a yard high, more or less, 
stoutish; terete and striate, very leafy, the leaves in twos or 
threes or alternate, mostly oblong-lanceolate, from repand to 
coarsely crenate or crenate-dentate, sparsely scabrous on both 
faces, the margins strongly so, the uppermost ovate, sessile 
by a broad and half-clasping base: heads large, long-pedun- 
cled; bracts of involucre ovate, obtuse or acute, puberulent 
and scabrous-ciliate: achenes large, nearly } inch long in- 
clusive of the wings, these broadest at the summit, ending 
to form an acutely triangular deep notch. 
Collected at Palma Sola, Florida, by Simpson, July, 1890; 
the specimens preserved in the U. S. Herbarium. 
