ABOUT THE OAKS OF THE UNITED STATES. 399 
Q. MicHauxtr, Nutt., such as it appears in the south and up to the lower Delaware River (Michaux, Canby, Com- 
mons), and to the lower Ohio (Dr. Schneck), would seem to be a well-marked species ; but my notes, p. 382, based 
upon too few specimens from a single locality, are no pe correct. It is certainly Q. Prinus palustris of Michie 
(the Q. P. discolor, quoted by Nuttall as synonym, is Q. bicolor), The tree grows in low grounds; has a gray, flaky 
bark ; leaves (usually large, 5-6 inches long) oval or peor regularly (commonly not deeply) dentate acute, obtuse 
or even cordate at base, eves’ thick and very soft downy below, rarely only slightly pubescent or even almost gla- 
brous (in Delaware, A. nons) ; male flowers mostly 10-androus ; fruit the largest of the Prinus group, short- 
peduncled, cup shallow, a or flat below, with deltoid, acute, rigid, distinctly imbricate scales, without any fringe. 
— Distinct as this tree seems to be, a series of forms, apparently common from the Delaware (Canby, Commons) to the 
Potomac (L. F. Ward, Dr. Vasey), evidently unite it, contrary to the views of most American botanists, with Q. bicolor. 
DeCandolle (Prod. 1. ¢. p. 20) already assumed their ide entity ; he, however, on the next page, wrongly ake Michaux’ s 
Q. P. palustris for Q. Prinus. The leaves of this intermediate form are in some instances purely those of bicolor 
others more those of Michauwii ; the acorns are subsessile, middle sized, with a deeply hemispherical cup, and a 
regular, often knobby and sometimes appendaged scales. If these connecting forms were not so common in the region 
mentioned, I might feel inclined to take them for hybrids between two distinct species ; as it is, 1 must consider 
Q. Michauxii as a subspecies of bicolor. 
Prinus, Linn. Q. Prinus monticola, Michx. Q. montana, Willd. Only after visiting the Alleghany Mountains 
and their eastern slopes, and seeing thousands of these trees, have I fully realized zi accuracy of Michaux’s description 
in his Sylva, and have become convinced of the absolute specific difference of this tree from the other members of the 
Prinus group ; and, indeed, its peculiar bark and wood distinguish it from all pee white-oaks, I suppose it to be 
the type of Linnzeus’s Q. Prinus, because it is the most common of the group in Virginia, whence the original came from: 
arbor procera Virginiana, Pluk. ; foliis .. . . serratis denticulis rotundatis uniformibus, Linn. H. Cliff. — The bark of 
the young tree before the age of 10 0 r 12 years is smooth and even shining, of a purplish-brown color; then it begins to 
crack and in the old tree becomes thick (often 1-2 inches and more) and deeply cracked and farrowed without pawns 
off, so that Michaux could, not inaptly, compare it with the bark of the chestnut, which, however, is darker. The 
is more porous than that of other emote and is said to be not much more usefal than that of eden: and 
unfit for barrels to cae liquids. Though its proper home seems to be in the mountain districts, it is not rarely seen 
in the low country eastward. Westward it is common in the mountains of Tennessee and Geo and 
has been collected on ‘coal Lake in Western New York ; it is unknown in the Mississippi Valley prope. [391 (7)]} 
e leaves are eee often almost coriaceous, pale below with a short and close pubescence, obova 
insiicinee sometimes even acuminate, those of the lower branches of the tree often much wider and pelle than the 
leaves of the upper, ieceite branches ; teeth coarse and regular, obtuse, rarely larger, or occasionally almost obliterated 
in the sinuate margin ; the lateral nerves usually terminate above the most prominent part of the ace teeth, and 
even in the sinus and only in the most prominent teeth at their apex. Fruit short-peduncled ; cup deep, somewhat 
turbinate, tubercled — rough, as the descriptions express it ; base of the scales often raised in two knobs, between 
which the short and almost indistinct tip of the scale next below i is almost buried ; acorn large, sometimes 1-1} inches 
long and 1 inch thic 
Q. MiuLenseral.® Q. castanea, Mihl. ap. Willd. Q. Prinus acuminata, Michx., occurs scatteringly throughout 
the middle and northern Atlantic States, in rk Aude only on limestone soil (Porter), but its proper home is the 
Mississippi Valley, where it entirely supplants Q. Prinus, more commonly on limestone hills and ridges, but also 
abundantly in river bottoms. Its flaky, pale ash-colored, thin bark and very tough wood (light yellowish brown 
when mature, whence probably the popular name of “ yellow-oak”) distinguish it at once from Prinus, as do also the 
small globose or commonly ovate acorns in a subsessile, shallow, and thin cup covered si small canescent, obtusish, 
rarely much thickened scales. Leaves on petioles 3-1 or even 1} inches long, thinner, more membranaceous, below 
pale and with an inconspicuous down, usually sharper serrate, often with inflexed sea and either lanceolate with a 
long acumination, 5-6 inches long by 14-2 in width (the typical form of Michaux and Mihlenberg) or larger, some- 
times even in fertile specimens as much as 7 inches long and 5 wide, broadly ovate or obovate with more rounded teeth, 
which form has often been taken for Q. Prinus, but is in bark and fruit identical with the narrow-leaved form. 
Q. prinorvEs, Willd., distinguished from the last by its low stature, smaller, more undulate than sharp-toothed 
leaves on shorter (}-} inch long) petioles, and commonly by deeper cups with more tumid scales, is apparently well 
enough marked eastward, but westward, from Western Missouri to Kansas and Nebraska, where it abundantly bears 
shes only 1-3 or up to 30 feet high (Z. Hall, G. C. Broadhead), it runs into the arborescent Miihlenbergii. It is sug- 
gested that annual prairie fires are the main cause of the stunted growth of this low form (while other species are not 
affected in this manner), and that often large and knobby rootstocks are found to produce numerous shoots, fertile 
8 As Miihlenberg’s as well as Michaux’s name for this very distinct species is _ it seems fit to commem- 
orate the celebrated Pennsylvanian botanist’s name by this oak, which he had so well distinguis 
