49 
for us by Mr. Ernest J. Lederle, of the School of Mines: 
Silica (Si Og ) - - - - 39.85 
Alumina and Oxide of Iron (Al, O3 laa Fe, O3) 18.58 
Lime (CaO) - - - - - - 9.35 
Magnesia (Mg O) - - e : = ADS. 
From this it is seen that the magnesia constitutes about one- 
fifth of the entire ash of the plant, and is present in larger 
quantity than any other constituent except the silica. 
It should be remarked that the specimens seen from about 
Washington, D. C., and from Montgomery county, Md., are 
larger than those from the serpentine areas. The same may 
also be said of the specimens from Amherstburgh, Ontario, said 
by Mr. Macoun to grow in ‘damp woods,” and also of those 
from the West. In some respects these approach the forms 
referred by us to var. maximumt. 
In Meehan’s “Native Flowers and Ferns of the United 
States,” Vol. ii., plate 48, is an illustration of one of these large 
forms, made from a specimen collected in Bergen Park, Colo., at 
an altitude of 7,000 feet. If this drawing is correct, it very 
nearly represents our var. maximum, but we have not seen any 
specimens of this from the Rocky Mountain regions. 
Between Dr. Torrey’s original description in the American 
Journal of Science and Arts, in 1822, and his later description in 
the Flora of the State of New York, published in 1843, there is 
the following discrepancy: In the former the leaves are described 
as acute, and the capsules as shorter than the calyx, while in the 
latter the leaves are described as mosély obtuse, and the capsules 
as about twice as long as the calyx. This is, perhaps, to be 
accounted for by the original imperfect material. The latter 
description agrees with the characters of our var. oblongifolium. 
Var. VILLOSUM, n. var. Stem leaves lanceolate to ovate- 
lanceolate; capsules 2 to 24 times the length of the calyx; the 
whole plant densely villous-pubescent. (Plate LXV., f. 8.) 
C. villosum, Muhl., Cat., 46; Darlingt., Flor. Ces‘r., 2d Ed., 279. 
C. hirsutum, ? Darlingt., Florula Cestr., 54. ? 
C. oblongifolium, Darlingt., Flor. Cestr., 3d Ed., 33, in part; Torr, & Gray, Fi. 
N. A., i., 188, in part. 
Habitat. On serpentine rocks, Lancaster Co., Penn. (Porter); 
