1918] SARGENT—QUERCUS 443 
for distinguishing species, and in the case of Q. uiahensis trees occur with cups 
showing a complete gradation between those with much thickened scales and 
those with only slightly thickened scales. Trees with the thickened and with 
the thin cup-scales occur over the whole region occupied by the species, but 
var. submollis seems rather more abundant on the Colorado plateau in northern 
Arizona where Q. uiahensis and its variety are the largest and most abundant 
oaks, 
QUERCUS ANNULATA Buckley, Proc. Phil. Acad. 1860. 445, is 
the earliest specific name for this white oak of western Texas, which 
was first described as Q. obtusifolia var. breviloba by Torrey in 
Bot. Mex. Bound. Surv. 206. 1895, and later by me as Q. breviloba 
in Garden and Forest 8:93. 18 
Q. annulata grows on the dry limestone hills of central Texas and is a large 
or small shrub spreading into thickets, or rarely a tree 10-12 m. tall. I formerly 
united Q. Durandii Buckl. with this species. They both grow in the 
neighborhood of Austin, Texas, but the two trees differ in habit and in distri- 
bution, for Q. annulata is confined to the dry hills of central and western Texas, 
while Q. Durandii ranges eastward to Mississippi, Alabama, and Georgia, and 
is a large tree of bottom lands. They are well distinguished, too, by the larger 
leaves and by the shallower cups of the fruit of Q. Durandii. The leaves of these 
two oaks differ on different parts of the tree; on fertile branches they are usually 
covered below with pale tomentum; on lower branches and on vigorous shoots 
they are green and glabrous or nearly glabrous on the lower surface, and some- 
times all the leaves are green on the lower surface. Q. annulata is the com- 
monest “‘shin oak” on the Edwards Plateau of Texas, where with bushes 1-2 m. 
high it covers thousands of acres of dry limestone hills, or in the protection of 
bluffs and ravines occasionally becomes a tree 8-ro m. tall. 
Quercus MourtANnA Rydb.—This species must be added to the 
list of North American trees, for although usually a shrub not more 
than 1.5 m. high, E. J. Palmer has found it growing as a tree 
7-8 m. tall, with a trunk 3 dm. in diameter, in the shelter of bluffs 
and ravines, Nolan County, Texas. 
Q. Mohriana is common on the Staked Plains of Texas, and from Tom Green 
County northward it replaces Q. annulata Buckl. on the slopes and tops of dry 
calcareous hills. . 
QUERCUS VIRGINIANA Miller—The fact that there are two 
distinct principal forms of the live oak in the southern states appears 
to have escaped the attention of most authors who have written 
about this tree. On one of the forms the leaves are comparatively 
