406 ABOUT THE OAKS OF THE UNITED STATES. 
Macon Co., Ill., rather more glabrous but otherwise similar ; and Mr. L. F. Ward discovered one near Washington, — 
The selétiwahip to imbricaria is unquestionable, and among the lobe-leaved black-oaks we must look to one of the 
forms of coccinea for the other parent, as the acorns and especially the cup and its scales indicate. I have not seen 
very young leaves, but doubt not but that they are, like those of the other ¢mbricaria-hybrids, revolute on the edges. 
Three years ago, I found in St. Clair Co., Ill., 20 miles from St. Louis, in low, fertile woods where both 
rubra and jinbotcaria: form the bulk of the forest, a hybrid which I took to be an offspring of those species ; growth of 
the tree and bark like rubra; leaves of the lower limbs ample, 4-8 or 9 inches long, 2-6 inches wide, obtuse or cor- 
date, rarely acute, at base, the smaller more’ commonly oblong and entire, the larger ones oval or obovate, entire or 
sinuate, or with a few broad and shallow obtuse or triangular bristle-pointed lobes ; in June still downy on the lower 
surface; petioles 3-1 inch long, pubescent ; the nascent leaves revolute on the margins, but much less so than imbri- 
carva, and white-tomentose on both surfaces. — Now, since I have obtained upper branches and ripe fruit, I am con- 
vinced that rubra, though growing close by, is innocent of its existence, and that coccinea, forests of which grow on 
the hills a quarter of a mile off, must be one of the parents ; in short, that it is a form of Leana itself. The cup of 
the acorn is, to me, decisive ; it is turbinate, covered with rather large canescent scales, squarrose at tip, and very 
different from those of either rubra or imbricaria, but approaching those of coccinea. The globose see 7 lines in 
diameter, one-third covered by the cup, shows 22-25 black stripes, so common in many black-oaks. 
leaves of the fertile branches are cordate or obtuse at base, and almost all deeply runcinate-serrate, — This [541 (19) ] 
instance ought to make us very careful not too hastily to judge of the parents of a hybrid from the species 
growing nearest to it. 
ELLOS X COCCINEA, Q. HETEROPHYLLA, Michwx., is distinguished by the petioled leaves of lanceolate out- 
line, pest Sl sinuate, spinulose-dentate, coarsely serrate, or with simple, sometimes spreading or falcate, lobes; leaves 
of different form on the same tree and often on the same branch, the uppermost leaves usually entire ; 7 or some trees 
more oak entire, others more with dentate or with lobed leaves. . Youngest leaves strongly revolute, pubescent above, 
white-downy below; becoming glabrous in summer. Acorns subglobose to oval, 5-7 lines long, a little less wide, 
scarcely half immersed in the shallow-hemispherical, somewhat turbinate, canescent cups ; scales lanceolate, obtuse. 
Fruit of same size and very similar to that of falcata, but cup usually deeper and. with larger scales. 
ical specimen described by Michaux, found by him “in a field belonging to Mr. Bartram near Phila- 
delphia,” has long since been destroyed, but its offspring was introduced into Europe, and the trees now seen in Bar- 
tram’s garden in West Philadelphia, at Marshall’s place in Marshalltown, and in J. Hoopes’s garden in Westchester, as 
well as those of the European gardens at Verritre, Herrnhausen, and Prague, the latter fertile, are believed to be its 
seedlings. Only within the last ten or fifteen years the tree has been re-discovered, and now numbers of individuals 
are knoe in low woods on both sides of the Delaware below Philadelphia (6 miles east of Camden, Smith, Leidy, 
Burk, Martindale, and 2 miles west of Wilmington, Commons, Canby), often in groups together, jnsbably the sthigeing 
of some few original hybrid trees. 
A. De Candolle and others viewed this hybrid as a form of aquatica, others, as belonging to Phellos, while I was 
long inclined to follow Michaux in considering it as a distinct species. With aquatica, which does not grow within 
a hundred miles, it has no relationship; aside from other characters, the revolute vernation abundantly distinguishes 
it from that species; from Phellos it differs in the form and size of the leaves and their thick down in youth (in Phellos 
even the youngest leaves are almost glabrous), and in the larger acorn in a deeper cup bearing much larger and longer 
scales. That it is a hybrid is most probable on account of its great rarity and its so very variable foliage. One of 
its parents is undoubtedly Phellos ; for the other we must look among the lobe-leaved black-oaks of its neighborhood, 
alcata, or coccinea. While the sometimes falcate lobes of the hybrid and the similarity of its acorns point to 
the first, and its frequency in those localities to the second, we find the texture of the leaf and its reticulation, as well 
as size and form of the cup and its scales, intermediate between Phellos and tinctoria, and quite different 
from the other two species, and thus come to the conclusion that the former must be the parents. [542 (20) ] 
Q. ILIcrFouIa X coccinea, Robbins in Gray, Man. ed. 5, p. 454, discovered by Dr. Robbins at 
Uxbridge, Massachusetts, in 1855, of which I have seen flowering and fruiting specimens in the Cambridge Herba- 
rium, seems just intermediate between the two parents. “Tree 40 feet high, 19 inches in circumference, both parents 
within 4 rods” ; leaves 4-5} inches long, nearly 4 wide, sinuate-lobed, lobes acutate, mostly bristled-toothed toward 
their apex; youngest ones greenish pubescent above, canescent below, at maturity strongly reticulate (ilicifolia is very 
slightly so) and shining above, and with the branchlets lightly pubescent below ; cup deeper than in ‘licifolia, glab- 
rate. The persistent though light pubescence resembles #licifolia, while the shape of the leaf reminds one of rubra 
than coccinea. 
7 This is the case generally in are ae Sot hybrids, i ie. middle ones are lobed, etc. ; thus the lower branches also 
hybrids between entire-leaved and lobe-leaved species ; the often bear entire leaves, while the upper ones have more 
uppermost leaves of an axis are apt to raping while the lobed ones. 
