1918] SARGENT—CARYA 249 
had the 2 trees in mind when he described his C. texana, for when 
they grow together in dry sterile soil, as in the neighborhood of 
Denison, they both have thick nearly black fissured bark and can- 
not be distinguished except by the shape of the fruit. Farther 
north and in better soil the bark of C. arkansana is thinner, lighter- 
colored, and is inclined to separate into small thin scales. The 
unfolding leaves and the young branchlets of both trees are thickly 
covered with tawny pubescence mixed on the under side of the 
leaflets with small silvery scales. This pubescence distinguishes 
them and C. floridana from all the other species of the United States. 
The size and shape of the fruit and the thickness of the involucre 
do not afford good specific characters in Carya, and the nature of 
the bark is so dependent within certain limits on the soil in which 
the individual grows that this cannot be depended upon for dis- 
tinguishing species. The winter-buds on both trees are covered 
with brownish pubescence in which silvery scales are more or less 
scattered; and the long white hairs found at the apex of the scales 
of the former sometimes occur but are perhaps more often wanting 
from the scales of the latter. The thick tawny pubescence is the 
most distinct and constant character of all the forms of this tree. 
The form with obovoid fruit can perhaps best be treated as a 
variety which becomes 
15. CARYA BUCKLEYI var. arkansana, nov. var.—C. arkansana 
Sargent, Trees and Shrubs 2:203. pl. 181. 1913.—Differing from 
the type in the obovoid to ellipsoidal or ovoid fruit with a usually 
thicker involucre, and in the oblong more compressed pale-colored 
nuts. 
The type region of this tree is the valley of the Arkansas River at Van 
Buren, near Fort Smith, in the extreme western part of the state of Arkansas. 
It has been found growing in sandy soil near Vollmer, Knox County, Indiana 
(C. C. Deam, no. 18232, August 28, 1915), and it is common in northeastern 
Missouri, where it has been collected by the Reverend Joun Davis at a number 
of stations near Hannibal. It is the common hickory on the Ozark Mountains 
in northwestern Arkansas, where it is very abundant on dry rocky ridges at 
- elevations of 400-600 m., and occurs in several other parts of Missouri and in 
Arkansas and eastern Oklahoma. It is not rare in western Louisiana, where 
it has been collected in the neighborhood of Opelousas, at Winnfield, and near 
Alexandria. In Texas it is the common hickory from the coast to the base 
