Juglans nigra #3 (Black Walnut)

Black Walnut is a broad, rounded, native tree with an open crown. It must be planted as an overstory tree, as it does not tolerate shade from competition. The tannin juglone, from which the species name is derived, is an allelopathic chemical that is released from all parts of this plant. Allelopathy is the production of a substance that inhibits plant growth of nearby sensitive species, in this case even the seedlings of the mother plant.

Despite their possible toxicity to a limited list of other species, Black Walnuts are incredible trees, the most valuable of all our native nut trees aside from Pecans. The nuts are edible, though requiring a considerable amount of effort to extract from the husks (which themselves yield a rich brown dye or ink) and the wood has long been prized for furniture making.

Black Walnut is a valuable tree for wildlife, supplying large crops of nuts that comprise 10% of the Eastern Fox Squirrel’s diet, and hosting some 125 species of Lepidoptera. It is the preferred host plant for the Luna Moth and Royal Walnut Moth. Eastern Screech Owls roost in the branches of these stately trees.

Sources:
Native Trees, Shrubs, & Vines by William Cullina
Eastern/Central Medicinal Plants and Herbs by Steven Foster and James A. Duke
Missouri Botanical Garden
Lady Bird Johnson Wildflower Center
USDA Forest Service

Photo Credit:
Mature Individual: Public Domain
Leaves and Nuts: Public Domain
Mature Trunk: Rhododendrites, CC BY-SA 4.0, via Wikimedia Commons
North American Champion: Gobywalnut, CC BY-SA 4.0, via Wikimedia Commons