Studies of Trees Part 10

[Ill.u.s.tration: FIG. 66.--A s.h.a.gbark Hickory Tree.]

Leaf: The leaf is compound, consisting of 5 or 7 leaflets, the terminal one generally larger.

Form and size: A tall, stately tree--the tallest of the hickories--of rugged form and fine symmetry, see Fig. 66.

Range: Eastern North America.

Soil and location: The s.h.a.gbark hickory grows in a great variety of soils, but prefers a deep and rather moist soil.

Enemies: The _hickory bark borer_ (_Scolytus quadrispinosus_) is its princ.i.p.al enemy. The insect is now killing thousands of hickory trees in the vicinity of New York City and on several occasions has made its appearance in large numbers in other parts of the country.

Value for planting: It is difficult to transplant, grows slowly and is seldom found in nurseries.

[Ill.u.s.tration: FIG. 67.--Bud of the s.h.a.gbark Hickory.]

Commercial value: The wood is extremely tough and hard and is used for agricultural implements and for the manufacture of wagons. It is excellent for fuel and the nuts are of great value as a food.

Other characters: The fruit is a nut covered by a thick husk that separates into 4 or 5 segments. The kernel is sweet.

Other common names: _Sh.e.l.lbark hickory_.

MOCKERNUT HICKORY (_Hicoria alba_)

[Ill.u.s.tration: FIG. 68.--Bark of the s.h.a.gbark Hickory.]

Distinguishing characters: The *bud* is the largest among the hickories--nearly half an inch long--is hard and oval and covered with _yellowish brown_ downy _scales_ which _do not project_ like those of the s.h.a.gbark hickory, see Fig. 69. The twigs are extremely coa.r.s.e. The *bark* is very tight on the trunk and branches and has a _close_, hard, _wavy_ appearance as in Fig. 70.

Leaf: The leaf consists of 5, 7 or 9 leaflets all of which are large and p.u.b.escent and possess a distinct resinous odor.

Form and size: A tall tree with a broad spreading head.

Range: Eastern North America.

Soil and location: The mockernut hickory grows on a great variety of soils, but prefers one which is rich and well-drained.

Enemies: The same as for the s.h.a.gbark hickory.

Value for planting: It is not commonly planted.

Commercial value: The wood is similar to that of the s.h.a.gbark hickory and is put to the same uses.

Other characters: The fruit is a nut, larger and covered with a sh.e.l.l thicker than that of the s.h.a.gbark. The husk is also thicker and separates into four segments nearly to the base. The kernel is small and sweet.

Other common names: _Bigbud hickory_; _whiteheart hickory_.

Comparisons: The _pignut hickory_ (_Hicoria glabra_), sometimes called broom hickory or brown hickory, often has a s.h.a.ggy bark, but differs from both the s.h.a.gbark and the mockernut hickory in possessing buds very much smaller, twigs more slender and leaflets fewer. The nut has a thinner husk which does not separate into four or five segments. The tree prefers drier ground than the other hickories.

[Ill.u.s.tration: FIG. 69.--Bud of the Mockernut Hickory.]

The _bitternut_ (_Hicoria minima_) can be told from the mockernut and other species of hickory by its bud, which has no scales at all.

The color of its bud is a characteristic orange yellow. The bark is of a lighter shade than the bark of the mockernut hickory and the leaflets are more numerous than in any of the hickories, varying from 7 to 11. Its nuts are bitter.

BLACK WALNUT (_Juglans nigra_)

Distinguishing characters: By cutting a twig lengthwise, it will be seen that its *pith* is divided into little _chambers_ as shown in Fig.

71. The bud is dark gray and satiny. The bark is dark brown and deeply ridged and the fruit is the familiar round walnut.

[Ill.u.s.tration: FIG. 70.--Bark of the Mockernut Hickory.]

Form and size: A tall tree with a spreading crown composed of stout branches. In the open it grows very symmetrically.

Range: Eastern United States.

Soil and location: The black walnut prefers a deep, rich, fertile soil and requires a great deal of light.

Enemies: The tree is a favorite of many caterpillars.

Value for planting: It forms a beautiful spreading tree on open ground, but is not planted to any extent because it is hard to transplant.

It grows slowly unless the soil is very deep and rich, develops its leaves late in the spring and sheds them early in the fall and produces its fruit in great profusion.

Commercial value: The wood is heavy, strong, of chocolate brown color and capable of taking a fine polish. It is used for cabinet making and interior finish of houses. The older the tree, usually, the better the wood, and the consumption of the species in the past has been so heavy that it is becoming rare. The European varieties which are frequently planted in America as subst.i.tutes for the native species yield better nuts, but the American species produces better wood.

[Ill.u.s.tration: FIG. 71.--Twig of the Black Walnut. Note the large chambers in the pith.]

[Ill.u.s.tration: FIG. 72.--Twig of the b.u.t.ternut. Note the small chambers in the pith.]

Other characters: The _fruit_ is a large round nut about two inches in diameter, covered with a smooth husk which at first is dull green in color and later turns brown. The husk does not separate into sections. The kernel is edible and produces an oil of commercial value.

The _leaves_ are compound and alternate with 15 to 23 leaflets to each.

Comparisons: The _b.u.t.ternut_ (_Juglans cinerea_) is another tree that has the pith divided into little chambers, but the little chambers here are shorter than in the black walnut, as may be seen from a comparison of Figs. 71 and 72. The bark of the b.u.t.ternut is light gray while that of the black walnut is dark. The buds in the b.u.t.ternut are longer than those of the black walnut and are light brown instead of gray in color. The form of the tree is low and spreading as compared with the black walnut. The fruit in the b.u.t.ternut is elongated while that of the black walnut is round. The leaves of the b.u.t.ternut have fewer leaflets and these are lighter in color.

GROUP X. TULIP TREE, SWEET GUM, LINDEN, MAGNOLIA, LOCUST, CATALPA, DOGWOOD, MULBERRY AND OSAGE ORANGE

TULIP TREE (_Liriodendron tulipifera_)

Distinguishing characters: There are four characters that stand out conspicuously in the tulip tree--the *bud*, the *trunk*, the persistent *fruit cups* and the wedged *leaf*.

The bud, Fig. 74, about three-quarters of an inch long, is covered by two purplish scales which lend special significance to its whole appearance. The trunk is extremely individual because it rises stout and shaft-like, away above the ground without a branch as shown in Fig. 73. The tree flowers in the latter part of May but the cup that holds the fruit persists throughout the winter. The leaf, Fig. 75, has four lobes, is nearly as broad as it is long and so notched at the upper end that it looks different from any other leaf.

[Ill.u.s.tration: FIG. 73.--The Tulip Tree.]

[Ill.u.s.tration: FIG. 74.--Bud of the Tulip Tree.]