Black locust
Robinia pseudoacacia
Family · Fabaceae · Poisonous
Read this before the sheet
This plant, or one that resembles it, is dangerous. Identifying is not authorising: no app has the authority to tell you that you may eat or touch a plant.
Emergency
The tree with paired thorns and sweet-scented white racemes that fills roadsides and banks in May. It came from North America, suckers everywhere from the roots and is among the hardest invaders to stop.
Roadsides and waste ground · Town and roadside · Streams and ditches · Fields and pasture
Also known asfalse acacia, locust tree
How to tell it
Two straight hard thorns at the base of each leaf, one on each side, which is the infallible mark. Compound leaves of nine to twenty-one oval leaflets that fold at night. Hanging white racemes of pea flowers, strongly scented. Bark deeply furrowed into ropes.
What it is confused with
Silver wattle
Acacia dealbata
Silver wattle has twice-divided leaves in very fine silvery grey segments and yellow ball flowers in winter; black locust has large oval leaflets, paired thorns and white racemes in May. Both are invasive.
What it is for
The flowers were eaten fried in batter in France and Italy, but the rest of the tree is not: bark, leaves and seeds contain robin and robinin, both toxic, and there are recorded cases of children and horses poisoned by chewing bark. The wood is rot-proof and the best vine stake there is.
The law says
A listed invasive alien species in Portugal. Do not plant or propagate it.
Where it occurs
Each square is an area with recorded observations of this plant. The lighter background is the set of areas where any of the entries has been observed, and serves as a reference. Note what this is not: it is not where the plant lives, it is where people record it, so trails and towns always look fuller than the mountains. Data from GBIF.
Sources
Community
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