See Map: C 
BLACK WALNUT 
Juglans nigra 
Like many of the Garden’s trees, such as 
oaks, hickories, elms, birches, and others, 
Vp walnuts are pollinated by wind. Unlike 
We showy flowers that attract insect or bird 
a rah is pollinators, the wind-pollinated walnut 
Exe’ Pa 8 flowers are small and inconspicuous. 
, RS i; ~The male flowers are grouped into 
a7 nck elongate clusters called catkins; and the 
S A S ‘Mh jn 
SF, at female flowers (which grow into the 
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at ‘~ = familiar walnuts) are in clusters of 2-5 
WN | LR and look like tiny eggs, each with two 
big bunny ears on top. The “ears” are 
| the stigmas, which work like antennae to 
Winter Summer capture airborne pollen grains as step 
one in the sexual cycle. 
Walnuts are delicious, especially in such delicacies as maple walnut 
ice cream. But all pleasures have their costs—gathering walnuts incurs 
the risks of stained hands and clothing (the husks were once used for 
dyes), and the husks cause allergic reactions in some people. Worse, the 
walnut meats are exasperatingly difficult to remove. This is advantageous 
for the tree, since squirrels gather, nibble, and bury (plant from the tree’s 
standpoint) walnuts often without destroying the meat, which is the 
embryo that grows into a new tree. 
Pickled walnuts are eaten in England and were popular in colonial 
America. To make them, half-grown walnuts in their husks are boiled in 
brine, then wiped scrupulously clean and placed in jars filled with boiled, 
spiced vinegar. 
Nuts of the closely related butternut (Juglans cinerea) yield abundant 
oil when split and boiled. The oil and nutmeats float to the surface, are 
skimmed off, and mashed into butternut butter. 
A year-round distinction between butternuts and black walnuts, both 
of which are Missouri natives, can be seen in the scar left when a leaf 
drops off of a twig. In butternut, the scar has a flat top, while in black 
walnut, the scar top is notched. The nuts of the butternut are elongate (vs. 
globe-shaped on the black walnut) and are sticky. 
Black walnut trees have become rare in the wild, not from disease, but 
because of their value as sources of fine, dark, beautifully grained wood 
prized for furniture, interior trim, veneer, and gunstocks. Because of the 
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