t ae 
JUGLANDACEAE OF THE UNITED STATES. 37 
white elm, but not shaggy; twigs often nearly red; fruit 
ellipsoidal to subglobose, rarely apophysate, the evident 
articulation close to its base; husk splitting almost to the 
base, often at first with raised lines along the sutures; nut 
gray or brownish, somewhat angled.— From the Mississippi 
Valley eastward, and from Canada to the Gulf, — mostly 
in uplands.— Pl. 8, 14, f. 3-5, 17, f. 9-14. 
Var. vILLosaA, Sargent.— Bark deeply fissured and very 
rough, but not at all shaggy; twigs very slender, red, 
mostly tomentose; fruit about as in the preceding variety ; 
nut mostly very brown, thick shelled and strongly angled, 
resembling the Mockernut.— Missouri, on flinty hills.— 
Pl. 9, 14, f. 6, 18, f. 1-2. 
Var. microcarPa (Nuttall) Sargent. — Bark more or less 
shaggy, often as rough as inthe Shagbark; fruit subglobose ; 
husk often glossy, splitting nearly to the base; nut mostly 
gray or whitish, angled, rather thin shelled for the group, 
the kernel sweet.— Same range as the variety odorata.— 
FI. 10, 34, f2.3517,'1. 7-3, 
Of all of the hickories, this is the most variable, as it is 
now understood, and I am far from satisfied with any 
arrangement of its forms that has yet appeared. In the 
character of the bark, form and dehiscence of fruit, and 
size, shape, color, hardness and degree of angling of the 
nut, differences are met with that would generally furnish 
specific or at least varietal characters, and to acertain extent 
this is true of thenumber of the leaflets ; yet these differences, 
which individually are marked, occur so variously combined 
that little dependence can be placed on them separately. 
It seems evident, however, that the typical eastern Pignut, 
with nearly indehiscent husk, does not occur west of the 
Alleghenies, being replaced in the west by the dehiscent 
fruited form that I have designated as variety odorata, 
which so insensibly merges into microcarpa as to make any 
separation of these two purely arbitrary, unless the shaggy 
bark of the latter furnishes a character always to be 
trusted by association with the whiter, thinner shelled nuts 
