Spiny winter twig
Spineless winter twig
In winter - frequently parasitized by mistletoe
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.
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
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
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.