In common language, the term Acacia is often applied to species of the
genus Robinia which also belongs to the family Leguminosae, though to
a different section.
R. pseudacacia, the False Acacia or Locust Tree, one of the most valuable
timber trees of the American forest, where it grows to a very large size,
was one of the first trees introduced into England from America, and is
cultivated as an ornamental tree in the milder parts of Britain, forming
a large tree, with beautiful pea-like blossoms.
The timber is supposed to unite the qualities of strength and durability
to a degree unknown in any other kind of tree, being very hard and close-grained.
It has been extensively used for ship-building, being superior for the
purpose to American Oak, and is largely used in the construction of the
wooden pins called trenails, used to fasten the planks to the ribs or
timber of ships. Instead of decaying, it acquires an extraordinary degree
of hardness with time. It is also suitable for posts and fencing and other
purposes where durability in contact with the ground is essential, and
is used for axle-trees and other mechanical purposes, though not for general
purposes of construction.
The roots and inner bark have a sweetish, but somewhat offensive and
nauseating taste, and have been found poisonous to foraging animals.
Medicinal Action and Uses
The inner bark contains a poisonous proteid substance, Robin, which possesses
strong emetic and purgative properties. It is capable of coagulating the
casein of milk and of clotting the red corpuscles of certain animals.
Tonic, emetic and purgative properties have been ascribed to the root
and bark, but the locust tree is rarely, if ever, prescribed as a therapeutic
Occasional cases of poisoning are on record in which boys have chewed
the bark and swallowed the juice: the principal symptoms being dryness
of the throat, burning pain in the abdomen, dilatation of the pupils,
vertigo and muscular twitches; excessive quantities causing also weak
and irregular heart action.
Though the leaves of Robinia have also been stated to produce poisonous
effects careful examination has failed to detect the presence of any soluble
proteid or of alkaloids, and by some the leaves have been recorded as
even affording wholesome food for cattle.
The flowers contain a glucoside, Robinin, which, on being boiled with
acids, is resolved into sugar and quercetin.