382 ] ENGELMANN-—OAKS OF THE UNITED STATES. 11 
•covers the acorn scarely one-half, usually three-fourths, and occasionally 
•entirely; the margin is profusely or sparsely fringed. —Throughout the 
north-west, north of the Missouri river, a low scrubby form is found, which 
might be designated as var. deflressa, as it is undoubtedly the obtusiloba 
j 3 . depressa, Nutt. gen. 2, 215, which has smaller leaves and much smaller 
acorns than the species, but is clearly a form of macrocarpa. 
3. Q. Mickauxii, Nutt.'gen. 2, 215, excl. syn.—The figure of Michaux, 
quoted by Nuttall, refers to bicolor , and none of his figures represent 
our plant. Elliott adopts Nuttall’s name, but Chapman as well as DeCan- 
dolle consider it a form of Prinus. Prinus was described by Linnaeus 
with foliis obovatis utrinque acuminatis , which sufficiently well agrees 
with all the forms of Prinus proper. Our plant is distinguished by having 
the leaves obtuse, or mostly cordate, at base; thicker, more leathery, and 
tomentose, on the lower side; and the male flowers io-androus. All the 
forms of Prinus proper have a very deciduous pubescence on the lower 
side of the leaf, which is acute or acutish at base. 
4. Q. Prinus , Lin., would then comprise Michaux’s varieties, palustris, 
monticola, and acuminata. 
5. ^>. undulata , Torr., has been treated of in the introduction to this 
paper; the different forms, there also enumerated, are — a. Gambelii (^. 
Gambeliii , Nutt, and probably «^. Drummondii , Liebm.) ; ( 3 . Gunnisoni 
(«^. alba , var. Gunnisoni , Torrey'i; y. Jamesii, Torrey’s original plant, 
figured in Ann Lyc. N.Y. 2, t. 4; the original figure reproduced with slight 
alterations in Nuttall’s N. Am. Sylv. 1, t. 3; 6 . Wrightii , often confounded 
-With Q. Emoryi, and apparently one of the forms comprised by Liebmann 
in his Q. pungens. Q. oblongifolia, Torr., and ^>. grisea Liebm., seem 
to be forms with more or less entire leaves; or the latter may perhaps have 
to be referred to the Mexican «^. microphylla. 
6- ^>. dumosa, Nutt., N. Am. Sylva, 1. p. 7 ; Torrey, Bot. Mex. Bound, 
p. 207. «^>. acutidens, Torr. ib. tab. 51, is a larger form of the same. 
berberidifolia , Liebm., DeProd. 16, 2, p. 36, seem to belong here either 
entirely or at least in part. A shrub of the southern part of California, 
often very squarrose, sometimes with slender and erect branches; leaves 
oval, obtuse, often cordate or obtuse at base, spinous-dentate or sometimes 
entire^ dark green above, hoary tomentose or pubescent below, from \ to I 
or sometimes 1 inch long; fruit sessile; cup strongly tuberculate, black, 
between 2 and 6 lines in diameter; acorn large for the size of the plant, 
oval, or small and narrow. 
7. Emoryi, Torr. Emory Rep. 1848, p. 15 L t. 9, hastata , Liebm. 
Quite distinct from «^>. undulata var. Wrightii, which is often confounded 
with it; the peduncled acorryof Torrey’s/figure belong to that form 
of undulata. This pretty/Arizonian species was collected by Emory in 1846, 
and soon afterwards by Wright, and then not again until Dr. Rothrock, 
a year or two ago, brought back fine specimens from Lieut. Whipple’s Ex¬ 
pedition. The leaves are not roundish or oval and pale as in Wrightii , 
but lanceolate, cordate at base, and dark green; the acorns in all the 
cm 
2 3 4 5 6 7 8 9 10 
copyright reserved 
