The legume trees
Pea-family trees that fix their own nitrogen, feed livestock and soil, root from a fence-post cutting, and flower spectacularly.
- 01
Trees№ 0475 minBlack Locust: Rot-Proof Timber, Nitrogen, and a Bad Reputation
A nitrogen-fixing tree with fence posts that outlast concrete — and one of the most aggressively invasive trees in Europe.
- 02
Trees№ 1044 minCoral Tree: Scarlet Flowers, Living Fences, and Nitrogen for Free
A thorny tropical legume that blazes with red bird-flowers on bare branches, roots from a cut stake to make an instant living fence, fixes nitrogen — and hides toxic seeds.
- 03
Trees№ 2273 minInga: The Ice-Cream Bean That Grows Alleys of Fertility
A fast tropical legume with sweet cotton-candy pods, that fixes nitrogen, shades out weeds, and anchors 'inga alley cropping' — a system that lets farmers grow food on the same plot for good instead of burning new forest.
- 04
Trees№ 1573 minFaidherbia: The Fertiliser Tree That Grows Backwards
A Sahelian acacia that does everything the wrong way round — dropping its leaves in the rainy season and leafing up in the dry — so that crops thrive right beneath it, fed by its nitrogen and shaded by nothing. Africa's great 'evergreen agriculture' tree.
- 05
Trees№ 4243 minSesbania: The Fast Legume With Flowers You Eat
Quick, soft, short-lived legumes that fix nitrogen fast enough to green a rice field in weeks — and whose big hummingbird-shaped flowers, borne by the hundred, are cooked and eaten as a vegetable across Asia.
- 06
Trees№ 3664 minPongamia: The Nitrogen-Fixing Tree That Might Actually Fuel Us
A tough coastal legume whose oil-rich seeds lit lamps and repelled pests for centuries — now seriously pursued as a biofuel and reforestation tree, having learned the hard lessons of the jatropha bust.
- 07
Trees№ 4803 minTagasaste: The Evergreen Fodder Tree That Feeds Stock and Bees
A fast, drought-hardy Canary Islands legume — 'tree lucerne' — that fixes nitrogen, stays green and leafy through summer drought when pasture fails, and pours winter nectar for bees.
- 08
Trees№ 2033 minGum Arabic: The Acacia Sap in Half Your Groceries
A thorny Sahelian acacia that bleeds a water-soluble gum used to emulsify soft drinks, bind sweets, coat pills, and float watercolours — a Sahara-edge crop that survives where almost nothing grows.
- 09
Trees№ 3834 minRain Tree: The Great Umbrella That Sleeps at Night
A vast, spreading legume that shades whole courtyards under an umbrella crown, folds its leaves shut at nightfall and before rain, fixes nitrogen, drips sweet pods for livestock, and turns into treasured monkeypod wood.
- 10
Trees№ 2174 minHoney Locust: Vicious Thorns, Sweet Pods, and a Ghost of Lost Megafauna
A legume tree armoured with branching spikes, hung with sugary pods, that turns out not to fix nitrogen — and whose fruit was built for animals that no longer exist.