Honey Locust Three-thorned Acacia

=Habitat and Range.=--In its native habitat growing in a variety of

soils; rich woods, mountain sides, sterile plains.



Southern Ontario.



Maine,--young trees in the southern sections said to have been

produced from self-sown seed (M. L. Fernald); New Hampshire and

Vermont,--introduced; Massachusetts,--occasional; Rhode

Island,--introduced and fully at home (J. F. Collins); Connecticut,-- ot

reported. Probably sparingly naturalized in many other places in New

England.



Spreading by seed southward; indigenous along the western slopes of

the Alleghanies in Pennsylvania; south to Georgia and Alabama; west

from western New York through southern Ontario (Canada) and

Michigan to Nebraska, Kansas, Indian territory, and Texas.



=Habit.=--A medium-sized tree, reaching a height of 40-60 feet and a

trunk diameter of 1-3 feet; becoming a tree of the first magnitude in

the river bottoms of Ohio, Kentucky, and Tennessee; trunk dark and

straight, the upper branches going off at an acute angle, the lower

often horizontal, both trunk and larger branches armed above the axils

with stout, sharp-pointed, simple, three-pronged or numerously branched

thorns, sometimes clustered in forbidding tangles a foot or two in

length; head wide-spreading, very open, rounded or flattish, with

extremely delicate, fern-like foliage lying in graceful planes or

masses; pods flat and pendent, conspicuous in autumn.



=Bark.=--Trunk and larger branches a sombre iron gray, deepening on old

trees almost to black; yellowish-brown in second year's growth; season's

shoots green, marked with short buff, longitudinal lines; branchlets

rough-dotted.



=Winter Buds and Leaves.=--Winter buds minute, in clusters of three or

four, the upper the largest. Leaves compound, once to twice pinnate,

both forms often in the same leaf, alternate, 6 inches to 1 foot long,

rachis abruptly enlarged at base and covering the winter buds: leaflets

18-28, 3/4-1-1/4 inches long, about one-third as wide, yellowish-green



when unfolding, turning to dark green above, slightly lighter beneath,

yellow in autumn; outline lanceolate, oblong to oval, obscurely

crenulate-serrate; apex obtuse, scarcely mucronate; base mostly rounded;

leafstalks and leaves downy, especially when young.



=Inflorescence.=--Early June. From lateral or terminal buds on the old

wood, in slender, pendent, greenish racemes scarcely distinguishable

among the young leaves; sterile and fertile flowers on different trees

or on the same tree and even in the same cluster; calyx somewhat

campanulate, 3-5-cleft; petals 3-5, somewhat wider than the sepals, and

inserted with the 3-10 stamens on the calyx: pistil in sterile flowers

abortive or wanting, conspicuous in the fertile flowers. Parts of the

flower more or less pubescent, arachnoid-pubescent within, near the

base.



=Fruit.=--Pods dull red, 1-1-1/2 feet long, flat, pendent, and often

twisted, containing several flat brown seeds.



=Horticultural Value.=--Hardy throughout New England, grows in any

well-drained soil, but prefers a deep, rich loam; transplants readily,

grows rapidly, is long-lived, free from disease, and makes a picturesque

object in ornamental plantations, but is objectionable in public places

and highly finished grounds on account of the stiff spines, which are a

source of danger to pedestrians, and also on account of the long

strap-shaped pods, which litter the ground. There is a thornless form

which is better adapted than the type for ornamental purposes. The type

is sometimes offered in nurseries at a low price by the quantity.

Propagated from seed.






1. Winter buds.

2. Winter buds with thorns.

3. Flowering branch.

4. Sterile flower, enlarged.

5. Flowering branch, flowers mostly fertile.

6. Fertile flower, enlarged.

7. Fruiting branch.

8. Leaf partially twice pinnate.





=Robinia Pseudacacia, L.=