THE LOCUSTS, THE YELLOWWOOD, AND THE KENTUCKY COFFEE TREE
Family Leguminosæ
The _Leguminosæ_ are a large order of plants including many different
genera,—from the little clover by the wayside to the honey locust
trees, 140 feet high. The trees of the different genera are all
distinguished by their pod-like fruit,—the name _Leguminosæ_ being
given to this family on account of the leguminous or bean-like pods
which enclose the seeds.
They are interesting to study on account of the buds, which differ in
structure from the hidden buds of the locusts enclosed in the stem, to
the subpetiolar buds of the yellowwood, concealed under the leafstalks
through the summer, but conspicuous in winter after they have fallen.
[Sidenote: Common Locust
_Robinia pseud-acacia_]
_An irregular growing, slender tree, 70 to 80 feet high, with very
rough, deeply furrowed, often yellowish-looking bark. Slender twigs,
with inconspicuous thorns. Small, alternate triangular leaf-scars,
somewhat raised in the centre. The buds are superposed between the
thorns, and are entirely hidden by the leaf-scars. Fruit a pea-shaped
pod, four or five inches long._
The common locust is one of the few trees which is decidedly more
attractive in summer than in winter. The delicate texture and tender
green of the leaves and the pendulous racemes of white fragrant flowers
make the whole beauty of this tree, and in winter it seems rough,
straggling, and uncouth in its habit of growth, and utterly devoid of
either strength or grace. The common locust glories in a wealth of
summer sweetness and color, but in winter the absence of poise and
symmetry in its branches and its colorless stems make it seem shapeless
and dead.
The wood is heavy and strong, and durable when it is placed in contact
with the soil. It is used in ship-building and for posts. The bark is a
tonic used in homœopathic remedies.
[Illustration: COMMON LOCUST TREES
_Robinia pseud-acacia_
Page 130
]
The name, _Robinia_, was given to this genus in honor of Jean Robin, a
French botanist, and the gardener of Henry IV. of France. The specific
name, _pseud-acacia_ (false acacia), arose from the supposition
that this tree was a species of the Egyptian acacia from its prickly
branches and pinnate leaves, which are like those of that tree. It was
called “locust tree” by English missionaries who collected it first and
fancied that it was the tree that nourished John the Baptist in the
wilderness.
It was one of the first American trees to attract attention in Europe,
and it has been extensively cultivated there.
The locust is not a native of New England, but it grows wild south of
Pennsylvania and it is widely naturalized throughout the United States
east of the Rocky Mountains.
The clammy locust (_Robinia viscosa_) is a small tree or shrub easily
distinguished from the common locust by its stems and young branches,
which are clammy and sticky to the touch. It is a native of the
mountains of North Carolina, and it has been extensively cultivated as
far north as Eastern Massachusetts.
The specific name, _viscosa_, is from the Latin adjective meaning full
of birdlime, sticky, and refers to the peculiar clamminess of the stems.
_Robinia hispida_, the rose acacia, is an ornamental shrub cultivated
in gardens and found growing wild from Virginia southward. The specific
name, _hispida_ (bristly), refers to the long bristles on the
branches, leaves, and pods which distinguish this shrub from the other
species of the genus.
[Sidenote: Honey Locust
_Gleditsia triacanthos_]
_A large tree with a smooth dark bark, cracking in thick lateral plates
on old trees. Long, branching thorns growing in clusters out of the
trunk and on the branches. Smooth, shining brown twigs and prominent
U-shaped, alternate leaf-scars. There are no terminal buds, and the
lateral ones are superposed, inconspicuous, rounded, and partly
concealed in the stem. The fruit is a large, pea-like pod, often
hanging on the trees through the winter._
[Illustration: HONEY LOCUST
_Gleditsia triacanthos_
Page 132
]
The honey locust is a beautiful tree with a large trunk and wide,
loosely spreading branches. It is particularly interesting in winter on
account of the apparent absence of buds along the stems. But for the
rich brown color of the stems they might be thought dead until a cut
with a knife in the stem over the leaf-scars shows the little tender
buds tucked away out of sight. It is interesting, too, to find thorns
which are long enough to have little thorns branching from them. A
straight thorn seems formidable enough even on a rose stem, but a thorn
some ten inches long with eight thorns branching from it, each varying
from half an inch to two inches long, and this but one of a cluster
of thorns, keeps the trunk of the honey locust sacred from climbing
boys and from browsing cattle. The honey locust is more effective than
a barbed wire for fencing. The fruit is in the form of a flat, crooked
reddish brown pod from seven to eighteen inches long. These pods are
often twisted, and are carried easily by the wind over the top of the
snow, and young locusts are propagated in this way at a great distance
from the parent tree. Beer has been made by fermenting the inner
pulp of fresh pods, but it is more of an experiment than a customary
practice.
The wood of the honey locust is hard, strong, and durable when it is
placed in contact with the soil; it is used for posts and rails and for
making the hubs of wheels.
The generic name, _Gleditsia_, was given to it in honor of Gleditsch, a
German botanist; and the specific name, _triacanthos_ (three-thorned),
refers to the branching thorns.
The honey locust is not native in New England, although it is found
growing commonly. Young trees spring up from the seeds of cultivated
trees, and in this way it has spread and increased its range. It
is found growing wild from Pennsylvania south and west. There are
thornless varieties of this tree which are often cultivated.
[Sidenote: Yellowwood
_Cladrastis lutea_]
_A small tree, 20 to 50 feet high, with a smooth dark gray bark. The
stems are smooth and brown, with light colored conspicuous leaf-scars
in a circle around the subpetiolar buds. The buds are brown and very
hairy, each scale being covered with soft brown hairs. Pod-like fruit,
about two inches long._
The clean, smooth bark of the yellowwood, its delicate branches and
rich brown stems make this tree attractive in winter, in spite of
the fact that, like the locust, its greatest beauty is in its sweet
pendulous flowers and bright green leaves. The yellowwood is one of the
few trees which have subpetiolar buds, and the prominent leaf-scars
encircling the bud show that the base of the leafstalk covered it until
the leaf fell off in the autumn.
[Illustration: KENTUCKY COFFEE TREE
_Gymnocladus dioicus_
Page 135
]
The wood is used for making gunstocks and for fuel, and it also yields
a yellow dye, from which it takes its specific name, _lutea_,—yellow.
The generic name, _Cladrastis_, comes from two Greek words meaning
brittle branches, and was given to the tree on account of its fragile
branches, which are easily broken by the wind. The yellowwood,
or virgilia as it is sometimes called, is extensively cultivated
in gardens and it is found growing wild in Kentucky and Tennessee.
Professor Sargent says that it is one of the rarest and most local
trees of North America.
[Sidenote: Kentucky Coffee Tree
_Gymnocladus dioicus_]
_A large tree, 50 to 80 feet high, with rough bark. Large cane-like,
smooth, gray shoots somewhat roughened by prominent lenticles. Large
U-shaped, alternate leaf-scars with three or five bundle-scars. No
terminal bud, the lateral buds are (two or three) superposed, they are
inconspicuous, very silky to the touch, deep set and surrounded by an
incurved rim of the bark. Large, wide, thick pods, 5 to 10 inches long._
The Kentucky coffee tree is entirely destitute of small spray, and in
winter its thick, cane-like stems, without any perceptible buds, give
it a singular appearance of rigid bluntness. A more striking contrast
than the flat, fine sprayed branches of the hop hornbeam and the stout,
upright stems of the Kentucky coffee tree could not be imagined. The
early settlers in Kentucky made a drink from the seeds of this tree,
which they considered equal to coffee, but later when communication
with the seaport towns was established they gave up this drink for
real coffee, and the seeds have never been used since for that purpose,
although the tree has retained its name.
The wood is heavy, but not very strong. It is occasionally used in
cabinet making and for posts and rails.
The generic name comes from two Greek words meaning naked branch, and
has reference to the stout branches without spray; and the specific
name comes from two Greek words meaning of two households, and refers
to the male and female flowers which are found on separate trees. The
Kentucky coffee tree is found growing wild from New York southward and
westward, and it is occasionally cultivated in gardens and parks.
There are one or two other trees belonging to this family which are
found planted in gardens. Of these the laburnum (_Laburnum vulgare_),
a small tree 10 to 20 feet high, is perhaps the most familiar. It came
originally from Switzerland, and has been cultivated in our gardens for
its beautiful yellow flowers, “rich in streaming gold.” Another member
of the family cultivated for its flowers and found wild from New York
south and west is the redbud or Judas tree (_Cercis canadensis_). It is
a small tree with no terminal buds, and with spreading, oval flower
buds along the stems, which open before the leaf buds in the spring,
and cover the branches with deep-pink flowers.