eee 
ABOUT THE OAKS OF THE UNITED STATES. 397 
a geographical point of view, we notice that the black-oaks of the present day are see to [386 (2)] 
Fontes and are principally developed in the Atlantic part of North America. We have there 15 
yeti a single abnormal type, while west of the Great Plains and on the Pacific slope only : cae occur, 3 
receding from the normal type. Numerous black-oaks are found in Mexico and Central America; in 
a indolle’s soy teton 20 are enumerated with known maturation, and of 18, of which the fructification is not 
ascertained, some may also belong here. In the a period the black-oaks, it seems, extended into the Old World, 
just as many other recent North American type 
The white-oaks are more uniformly daactineed over the temperate parts of the northern hemisphere. We have 
on the eine ati 8 beri and 9 in the western half of the continent, only 2 of the latter abnormal. 
T e have ur flora nearly as many white-oaks as black-oaks; bat while the former are nearly equally 
site we ox and west, the latter predominate eastwar 
— A too hasty rear partly of specimens too far advanced, has led me into several 
errors. gs ert is caine only in par the white-oaks (in the European type of the genus, Q. Robur ; 
in our Q. < macrocarpa, Garryana, and in all ihe species of the Prinus group ; probably in lyrata, Douglasii, and 
he imbricate vernation is the rule for the balance of the white-oaks (Q. stellata, undulata, dwmosa, and 
shepictapia) ee for all the black-oaks, with the exception of the few species (p. 376) with revolute veunnkat In th 
oaks with imbricate vernation the outer leaves are always imbricate, but the inner ones are imbricate or oe or even 
slightly revolute on the margins in the species with thicker, firmer leaves (undulata, dumosa, chryso 
agrifolia, nigra, stein laurifolia, cinerea, Petco In the others, with broader and more lobed leaves: Coase, 
rubra, orgie is, falcata, e te.) the 2 or 3 innermost leaves are conduplicate. The inflexed vernation mentioned as occur- 
ring in Q. Catesbai, is also occasionally seen in falcata, evidently in oaks with slender-lobed leaves, but it is by no 
means ceteris al of no specific value 
The suggestion that the character of vernation would be an important assistance in classification, and in [387 (3)] 
the — of alliances of hybrids, has been verified by actual observation, as will be shown below. 
ge 3 The glandular colored pubescence appears on both sides of the young leaves in Catesbei, sinuata, and 
lichens on the lower side in chrysolepis and somewhat in stellata ; on the upper side in falcata, and also in Catesbei- 
laurifolia. I do not find this pubescence on seedlings of these species, nor is it often seen on the youngest leaves, but 
becomes developed when the leaf has attained } to $ of its full size 
The reticulation is generally more marked on the upper ‘hai on the lower side of the leaves, and in the black- 
oaks more than in the white-oaks ; an exception occurs in Q. falcata and (as already indicated) agrifolia ; in both the 
upper surface is almost smooth ; in etnerea and ilicifolia the ee is much less prominent than in most othe 
Page 377. The male aments are produced from scaly buds which are not further developed, or from the iveet 
part of branchlets, usually in the axils of bud-scales, or rarely rene the axils of the lowest leaves; thus often in Q. 
agrifolia. They are = simple, but in chrysolepis I find them often branching, such as they are described in the 
Asiatic section Pasan 
378, 1. 16 in 17, strike out the comma after “ connected,” “ differences” and “petiole.” Add in before 
“the ecthe 
L. 33. Four black-oaks with annual maturation, including Q. Emoryt. 
Page 379, ]. 22. Occasionally black-oaks are tend with cup-scales thickened at base ; Prof. Sargent has col- 
lected near Cambridge fruits of ilicifolia with this peculiarity, and it does not seem to be rare at all in northern forms 
of rw 
ee: from below. The abortive ovules are not oval and pendulous, but rather bottle-shaped bodies, suberect in 
ks. 
‘the white-oaks, hemitropous in the black-oa 
Q. 
y Le Emoryi, in every other respect a true black-oak with annual pie py has basal ovules, 
= skatlens remarkable instance of mere botanical characters not always coinciding with essential ones. Hence the word 
- aalear: ” in the first sentence of the following page, must be qualified by adding almost. 
Pag The following is believed to be a more correct enumeration and more natural arrange- [388 (4)] 
ment of our oaks. 
I. LEPIDOBALANUS, Endl. 
A. eases 
* Maturatio ann 
t Fo iia ecidua. 
Q. alba, lobata ( fruticosa 1), gorse stellata, macrocarpa, lyrata, bicolor (Michauxii), Prinus, Mihlenbergi: (pri- 
noides), Douglasii, undulata (pungens). 
+ t Folia persistentia. 
Q. oblongifolia, dumosa, reticulata, virens. 
1 The names in parentheses designate subspecies, 
