Juglans nigra – Black Walnut (eastern North America)
Habit: Splendid large tree, 20-30 m tall and wide, dominant, asymmetrical, loose round crown, broad; expansive; fast-growing, 60-90 cm a year.
Flowers: Monoecious in green catkins, April to May.
Fruits: Golfball-size fruits, sticky, shiny green, aromatic husks, very colourful; ovoid to round black-brown nuts inside, ripe from end of August, the oily core is edible, but the thick case is hard to open, strong taste.
Leaves: Pinnate, 30-50 cm long, lateral leaflets elliptical or lanceolate; shoots light green from end of May, later dark green; radiant light yellow in autumn, falling early at beginning or middle of September; aromatic; weathering quickly.
Trunk: Usually short, blackish bark with deep grooves; wood is very heavy, uncommonly hard and durable, very valuable.
Roots: Extremely deep; tolerates occasional floods.
Demands: Sun to light shade; tolerates heat, likes it warm to cool; frost hardy, sensitive to late frost, resistant to air and soil pollution, wind resistant.
Soil: Dry to very moist; neutral to very alkaline.
Hardiness: Zone 5b