JUGLAXDACEAE OF TUE UNITED STATES. 37 
white elm, but not shaggy ; twiirs often nearly red ; fruit 
ellip>oi{lal to sub<rlobo>e, rarely apophy^ate, the evident 
articulation clo»e to its ha<o : hu^k >plittinir almost to the 
ba.so, often at tir^t with ralM-d linr. aloiiir the >utures; nut 
gray or brownish, somewhat annled. — From the Mississippi 
Vafley eastward, and fr..m Canada to the Gulf , — mostly 
in uplands.— ri. 8, 14, f. 3-5, 17, f. 1>-U. 
Var, viLLOSA, 8arLn>nt. — Bark deeply fissured and very 
rough, but not at all .-h:«ggy: tulL'^ very .slender, red, 
mostly tomento>e; fruit alxuit'as in the pn'eedii^ir variety; 
nut mo.stly very brown, thick >hi'iletl aiul >tn.n.-iy an-h'd, 
resembling the Mockernut. — Mi^^ouri, on llinty hills. — 
PI. 9, 14, f. 6, 18, f. 1-2. 
Var. MTCROCARPA (Nuttall) Sargent. — Bark more or less 
shaggy, often as rough a.s intheShagbark ; 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 odoraia. — 
PI. 10, 14, f. 2, 17, f. 7-8. 
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 anirlin*: of the 
nut, differences are met with that would generally furni^i 
specific or at least varietal character-, and to a cert;un extent 
thisi^trueof the number of the leailet> ;yetthese differenees, 
which individually are marked, occur so variously combined 
that httle dependence can be placed oji th<'ni separately. 
It seems evident, however, that the tyjucal ea>tern Pignut, 
with nearly indehiscent husk, dues not occur west of the 
Alleghenies, being replaced in the we^t by the dehiscent 
fruited form that I have designated as variety odorafa^ 
which so iusen-ibly merges into microcarpa as to make any 
separation of the-e two purely arbitrary, unlo- the shaggy 
biu"k of the latter furnisher a character always to be 
trusted by association vriia the whiter, thinner shelled nuts 
