False-acacia
(Robinia pseudoacacia)
Compound
Pinnate
Alternate
Thorny

compound leaf

Winter twig
Spiny winter twig


Spineless winter twig

tree

In winter - frequently parasitized by mistletoe
In winter - frequently parasitized by mistletoe

flowers

distribution map

The pinnate leaves, with 3-9 pairs of leaflets and a terminal one, are arranged alternately. Each leaflet, 2.5-4.5 cm long, is almost hairless and bluish-green beneath. There are usually 2 spines at the base of the leaf stalks, especially on young shoots.

ID check

False-acacia is an introduced deciduous tree, up to 25 m tall, with a rounded outline made up of many fine, often zig-zag, branches and with a twisted and furrowed bark. It is often planted on light soils and spreads by seed and suckers.

The pea-like white flowers are arranged in hanging spikes, 10-20 cm long and appear in June.

Each flower is 15-20 mm long, sweet-smelling, with much nectar.

The smooth, brown pods release black, kidney-shaped seeds in autumn, but stay on trees all winter.

Facts

  • Like other members of the pea family it has bacterial nodules on its roots, which fix nitrogen from the air and so it can be used to establish cover on old colliery tips.

  • The hard, durable wood makes fencing posts which last longer than oak.

  • The Latin name 'Robinia' honours a French gardener, Jean Robin, who introduced the tree from N. America about 1600.

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