Juglans cinerea (Butternut) - 1 gal

Butternut, also called White 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 its possible toxicity to a limited list of other species, Butternuts are incredible trees. Their nuts are sweet, buttery and delicious. They are prized for their heartwood, though it is increasingly rare due to overharvesting and disease. The trees are endangered in their native range because of a fungus called butternut canker. This disease is incurable, widespread, and responsible for wiping out large portions of the population. Plant them with care, and expect that they will be relatively short-lived.
This smaller cousin of the Black Walnut is a valuable tree to wildlife, supplying large crops of nuts and hosting some 125 species of Lepidoptera, including the Banded Hairstreak, Royal Walnut Moth, and the Luna Moth.
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