The locust has of recent years been extensively planted for post timber.
It is very easily propagated from seedlings and grows rapidly. It is
adapted to all kinds of soil, except a wet one. It prefers a well
drained soil and seems to grow as fast in a loose clay soil as in a
black loam. When used for forest planting the spacing should be from 5 × 5
feet to 8 × 8 feet. The spacing should be governed by the quality of the
soil, and the amount of pruning that can be done. The locust has the
habit of having the terminal to end in a fork and having one or more
very large side branches. The best management requires that the very
large side branches be removed as soon as they are noted, and one part
of the terminal forks be cut off.
The locust until recently gave great promise of being an important tree
for planting sterile, washed and eroded slopes, on which it usually
thrives and in many cases grows thriftily. However, reports from all
parts of the State show that locust groves wherever planted are being
killed by the locust body borer. The locust has also been attacked by
the twig borer, bag worm and the leaf miner. At present there are no
known economic means of controlling these destructive pests, and until
they can be controlled, the planting of locust for commercial purposes
will not prove profitable.
=SIMARUBÀCEAE.= The Quassia Family.
=AILÁNTHUS.= Tree of Heaven.
=Ailanthus altíssima= (Miller) Swingle. Tree of Heaven. Stink Tree.
(_Ailanthus glandulosa_ Desfontaines). Plate 110. Medium sized trees
with dark gray bark, thin, rough or fissured on old trees; branchlets
very robust; twigs smooth; leaves compound and very large, especially on
coppice shoots, usually about 4-6 dm. long, odd-pinnate, arranged
spirally on the branchlets; leaflets 13-41, ovate-oblong, acuminate,
oblique at base, entire or with a few blunt teeth toward the base,
smooth or hairy when they unfold, becoming smooth at maturity, dark
green above, lighter beneath; flowers appear in June in large terminal
panicles, the staminate and pistillate on different trees; fruit
maturing in autumn, consists of many light brown, twisted and
broadly-winged samaras which are about 1 cm. wide and 4-5 cm. long.
=Distribution.=--A native of China. Introduced and spreading in cities,
and into fields and woods in the southern part of the State. The most
notable occurrence is in Jefferson County on the wooded bluffs of the
Ohio River between Madison and Hanover.
=Remarks.=--Where the sugar and black maple can not be used for shade
tree planting this tree should receive attention. It adapts itself to
all kinds of soils, and to all kinds of growing conditions such as
smoke, etc. The crown is of an oval or rounded type. It stands pruning
and injury to trunk or branches quite well. It is practically free from
all diseases and insect injury. The leaves appear late but they do not
fall until the first killing frost when they are killed, and frequently
practically all of the leaves will fall in one day. The staminate
flowers exhale a fetid odor for a few days which is about the only
objectionable feature in this tree. In order to obviate this objection,
nurserymen are now offering for sale pistillate trees which have been
grafted on common stock.
[Illustration: Plate 110.
AILANTHUS ALTISSIMA (Miller) Swingle. Ailanthus or Tree of Heaven.
(× 1/2.)]
=ACERÀCEAE.= The Maple Family.
=ÀCER.= The Maples.
Trees with terete branches; scaly buds; long petioled, opposite leaves;
fruit consists of two long-winged samaras which are joined at their
base, separating at maturity. The sap of some of the species, when
concentrated, yields the maple sugar and sirup of commerce.
Leaves trifoliate or pinnate 1 A. Negundo.
Leaves simple.
Winter buds blunt; flowers appear from lateral buds before
the leaves; fruit maturing in the spring or early summer.
Leaves entirely glabrous beneath at maturity, 5-lobed;
the two sinuses between the three largest lobes
generally somewhat closed, formed as it were by
the arcs of two circles which meet to form the
sinus, and which if they were extended outward
would cross each other within a few dm. of the
sinus; fruit more or less pubescent at maturity 2 A. saccharinum.
Leaves are never all entirely glabrous at maturity,
3-5 lobed; the two largest sinuses are generally
angular with straight sides which if extended
outward would never cross; fruit smooth at maturity.
Twigs smooth at maturity; leaves at maturity smooth
beneath except a few hairs in the axils of the
veins, or more rarely the entire lower surface
covered more or less with a short pubescence;
mature fruit generally 2-3.5 cm. long 3 A. rubrum.
Twigs more or less pubescent at maturity; leaves
beneath covered with a dense tomentum which
remains until maturity or sometimes becoming
scanty; fruit about 4-5 cm. long var. Drummondii.
Winter buds acute, sometimes somewhat blunt; flowers
appear from terminal buds after the leaves; fruit
maturing in the autumn.
Leaves yellow green beneath; base of the petiole of
the terminal leaves enlarged at the base, smooth
or somewhat pubescent about the enlarged base. 4 A. nigrum.
Leaves not yellow green beneath; base of the petiole
of the terminal leaves not enlarged, petioles smooth,
or if pubescent at the base the pubescence will be
more or less evident the entire length of the petiole.
Petioles smooth; leaves 3-5 lobed, blade as long
or longer than wide, not densely pubescent
beneath at maturity. 5 A. saccharum.
Petioles smooth; leaves 3-lobed, blades wider than
long. A. saccharum var.
Rugelii.
Petioles pubescent, rarely smooth; leaves 5-lobed,
rarely 3-lobed, the under surface densely
pubescent at maturity. A. saccharum var.
Schneckii.
=1. Acer Negúndo= Linnæus. Box Elder. Plate 111. A medium-sized tree
with a short trunk and round head; bark of young trees smooth and gray,
becoming thick on old trees, light to dark brown and more or less
furrowed or rarely somewhat flaky; twigs smooth and greenish; leaves of
average size are 1.5-3 dm. long, generally with 3 leaflets on the
flowering branches, sometimes 5 or rarely with 7, on sterile branches or
on growing shoots 3-7, the petioles generally 1/3-1/2 the length of the
leaf and glabrous or nearly so at maturity; leaflets all on stalks more
or less pubescent, the lateral stalks short, the terminal ones much
longer, leaflets of varying size and shape, the margins usually varying
from lobed to serrate or entire, pinnately veined, smooth above at
maturity and remaining more or less pubescent beneath, especially along
the veins; flowers appear just before the leaves the last of April or
the first of May, the staminate and pistillate on separate trees; fruit
matures late in summer, the body of the samara green and more or less
pubescent.
=Distribution.=--New England to Florida, west to Minnesota and south to
eastern Texas. In Indiana, it is found throughout the State in moist or
wet places along creeks and rivers, and infrequently on the highlands
along roadsides and fences. Its original distribution in the State can
only be conjectured. Judging from its tolerance to shade and its
habitat, and from the earliest reports of its occurrence in the State,
this species was quite rare in the northern part of the State, becoming
infrequent to frequent in its habitat in the southern part of the State.
Even today it is rather local in its distribution. I have never seen it
on the low mucky border of a lake.
=Remarks.=--This species on account of its rapid growth was formerly
much used in our area as a shade tree. It is believed that most of the
trees now found along roadsides, fences, clearings and on the drier
banks of streams are from seed distributed by the wind from planted
trees. This species is now little used as a shade tree and is never
recommended because it sheds its leaves early, and is subject to injury
from disease and insects.
[Illustration: Plate 111.