Black Walnut

Juglans nigra · also: eastern black walnut, noyer noir

How to ID it

Large tree with deeply furrowed dark bark and long pinnately compound leaves (15–23 leaflets)
Nuts fall as round, tennis-ball-sized green husks — solid, not sticky-hairy
Crush a leaf or scratch a twig: aromatic, spicy-citrusy walnut smell
Husks bruise brown-black and stain everything they touch

Safety

Safe to eat — the only nuisance is the husk, whose juglone and tannins stain skin and clothes a deep, near-permanent brown. Wear gloves and old clothes.
The nut meat itself is excellent; the staining is entirely in the husk. Juglone also harms many garden plants, so don't compost husks near beds.

Harvest

Collect the round green husks off the ground once they start dropping in mid-September. Take only firm ones; skip any that are mush. Wear rubber gloves — the husks stain hands brown for a week and ruin clothing permanently.

Prep

Remove the husk first: stomp them, or roll underfoot on pavement, then peel the blackening flesh away. Wash the hard shells, then cure the nuts by drying in a single layer in a ventilated spot for 2–4 weeks. Cracking is genuinely hard work — a vise or a heavy hammer on concrete beats a normal nutcracker. The meat is rich, dark, and intensely flavored, worth the effort.

Notes

Squirrels are fast competitors, so gather early. A stained-hands session is a rite of passage. Don’t dump the husks in a veggie bed — juglone suppresses many plants.