390 THANS. ST. LOUIS ACAD. SCIENCE. 



others with much smaller or longer acorns; in some the cup is scarcely 

 fringed. 



^. Michauxii, Nutt., such as it appears in the south and up to the lower 

 Delaware River (^Michaux, Canby, Commons), and to the lower Ohio (^Dr. 

 ScAneck), would seem to be a well marked species; but my notes, p. 3S2, 

 based upon too few specimens from a single locality, are not quite cor- 

 rect. It is certainly ^. Prinus palustris of Michaux (the ^. P. discolor, 

 quoted by Nuttall as synonym, is ^. bicolor). The tree grows in low 

 grounds ; has a gray, flaky bark ; leaves (usually large, 5-6 inches long) oval 

 or obovate, regularly (commonly not deeply) dentate acute, obtuse or even 

 cordate at base, generally thick and very soft downy below, rarely only 

 slightly pubescent or even almost glabrous (in Delaware, A. Commons) ; 

 male flowers mostly 10-androus; fruit the largest of the Prinus group, 

 short-peduncled, cup shallow, obtuse 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, Cojnmons') to the Potomac {L. F. Ward, Dr. Vasey), evidently 

 unite it, contrary to the views of most American botanists, with ^.bicolor. 

 DeCandolle (Prod. 1. c. p. 20) already assumed their identity ; he, however, 

 on the next page, wrongly quotes Michaux's <^. P. falustrls for J^. Prinus. 

 The leaves of this intermediate form are in some instances purely those of 

 bicolor, in others more those of il//c^aa«eV; the acorns are subsessile, mid- 

 dle sized, with a deeply hemispherical cup, and less regular, often knobby 

 and sometimes a'ppendaged 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, I must consider ^. Michauxii 

 as a subspecies of bicolor. 



<^. Prinus Lin., ^. Prinus monticola Michx., .^. ;«o»^a»a Willd. Only 

 after visiting the Alleghany Mountains and their eastern slopes, and see- 

 ing thousands of these trees, have I fully realized the accuracy of Michaux's 

 description in his Sylva and have become convinced of the absolute speci- 

 fic diflference of this tree from the other members of the Prinus group; and, 

 indeed, its peculiar bark and wood distinguish it from all other White- 

 oaks. I suppose it to be the type of Linnseus's =^. Prinus, because it is the 

 most common of the group in ^^irginia, whence the original came from : 



arbor procera Virgittiana, Pluck. ; foliis serratis denticulis rotundatis 



uniformibus, Lin. H. Cliff. — The bark of the young tree before the age of 

 10 or 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 furrowed without peeling off", so that Mi- 

 chaux could, not inaptly, compare it with the bark of the chestnut, which, 

 however, is darker. The wood is more porous than that of other White- 

 oaks, and is said to be not much more useful than that of Black-oaks, and 

 unfit for barrels to hold 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 Georgia, and 



