540 TRANS. ST. LOUIS ACAD. SCIENCE. 



few (sometimes more) coarse, triangular-lanceolate, acute, bristle-pointed 

 teeth, glabrous on both sides; about 4 inches long, i^ wide, rarely larger; 

 peduncles 3-4 lines long; cup moderately deep, turbinate at base, 6-7 lines 

 wide, 3- 4 high; ovate, obtuse scales, canescent, with bright brown margins. 



^. imbricaria X coccinea was first described and figured by Nuttall, 

 about thirty years ago, under -the name of ^. Leana, Nutt. Sylv. Contin. 

 1, tab. 5 bis; DC. 1. c. 62. The original tree was discovered by Mr. T. G. 

 Lea, near Cincinnati, and is still in existence; soon afterwards. Dr. S. B. 

 Mead found another tree in Hancock Co., Illinois. My specimen, obtained 

 from the first discoverer, has entire or sinuate or dentate or dentate- 

 lobed leaves, 4-6 inches long and half as wide, and even in September 

 slightly pubescent below; lobes acute and bristle-pointed or quite obtuse; 

 base .attenuated into a petiole 5-8 lines long; acorns similar to those of 

 coccinea, cup shallower with obtuse scales. The leaves in Nuttall's figure 

 have a cordate base. Dr. Mead's tree is similar to Lea's; leaves appa- 

 rently more commonly entire or undulate-sinuate, 5-7 inches long and half 

 as wide, obtusish at base on a petiole i inch long; the pubescence has 

 almost disappeared on thelower side of the autumnal leaf; acorns globose, 

 covered J-i by the canescent cup. Prof. G. C. Swallow found a similar 

 tree in Missouri ; Mr. E. L. Greene sends another specimen from Macon Co. , 

 Ills., rather more glabrous but otherwise similar; and Mr. L. F. Ward 

 discovered one near Washington. — The relationship to imbricaria is un- 

 questionable, and among the lobe-leaved Black-oaks we must look to one 

 of the forms oi 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 imbricaria - hybrids, 

 revolute on the edges. 



Three years ago, I found in St. Clair Co., Ills., 20 miles from St. Louis, 

 in low, fertile woods where both rubra and imbricaria 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 cordate, 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 

 ^-i inch long, pubescent; the nascent leaves revolute on the margins, but 

 much less so than imbricaria^ and white-tomentose on both surfaces. — 

 Now, since I have obtained upper branches and ripe fruit, I am convinced 

 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 oflf, 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 difterent from those of either 

 rubra or imbricaria, but approaching those of coccinea. The globose 

 acorn, 7 lines in diameter, one-third covered by the cup, shows 22-25 black 

 stripes, so common in many Black-oaks. The leaves of the fertile branches 



