Trees Worth Knowing Part 21

=The White Mulberry=

_M. alba_, Linn.

The white mulberry is a native of northern China and j.a.pan. From this region it has been extensively introduced into all warm temperate climates. Its white berries are of negligible character. It is the leaves that give this oriental mulberry a unique position in the economic world. They are the chosen food of silkworms. No subst.i.tute has ever robbed this tree of its preeminence, maintained for many centuries in its one field of usefulness.

The hardy Russian mulberries are derived from _M. alba_. These have done much to enrich the horticulture of our Northern states, but the parent tree, though it thrives in the eastern United States and in the South, has not been the means of establishing silk culture on a paying basis in this country.

=The Black Mulberry=

_M. nigra_, Linn.

The black mulberry, probably a native of Persia, has large, dark red, juicy fruits, for which it is extensively cultivated in Europe. In this country it is hardy only in the Southern and the Pacific Coast states. It is the best fruit tree of its family, yet no mulberry is able to take rank among profitable fruit trees. The fruits are too sweet and soft, and they lack piquancy of flavor. They ripen a few at a time and are gathered by shaking the trees.

The dark green foliage of the black mulberry gives ample shade throughout the season. Planted in the garden or in the border of the lawn where no walk will be defaced by the dropping fruits, the mulberry is a particularly desirable tree because it attracts some of our most desirable song-birds to build on the premises. Given a mulberry tree and a bird-bath near by, and the smallest city lot becomes a bird sanctuary through the summer and a wayside inn for transients during the two migratory seasons.

THE FIGS

The genus _ficus_ belongs to all tropical countries, and this remarkable range accounts for the six hundred different species botanists have identified. The rubber plant, popular in this country as a pot and tub plant, is one of the best-known species. In its East Indian forest home it is the "a.s.sam Rubber Tree." It may begin life as an air plant, fixing its roots in the crotch of another tree, in which a chance seed has lodged. A shock of aerial roots strikes downward and reaches the ground. After this the tree depends upon food drawn from the earth. The supporting host tree is no longer needed. The young rubber tree has by this time a trunk stiff enough to stand alone.

a.s.sam rubber, which ranks in the market with the best Brazilian crude rubber, comes from the sap of this wild fig tree, _Ficus elasticus_.

Clip off a twig of your leathery-leaved rubber plant and note the sticky white sap that exudes. In the highest priced automobile tires you find the manufactured product.

Dried figs have always been an important commercial fruit. These imported figs are from trees that are horticultural varieties of a wild Asiatic species, _Ficus Carica_. Smyrna figs are best for drying.

They form a delicious, wholesome sweet, which has high food value and is more wholesome than candy for children. Tons of this dried fruit are imported each year from the countries east of the Mediterranean Sea. Now California is growing Smyrna figs successfully.

The banyan tree of India is famous, striking its aerial rootlets downward until they reach the ground and take root, and thus help support the giant, horizontal limbs. These amazing trees, members of the genus _ficus_, sometimes extend to cover an acre or more of ground. To walk under one is like entering the darkness of a forest of young trees. By the clearing away of most of these aerial branches, a great arbor is made for the comfort of people in regions where the sun's rays are overpowering in the middle of the day.

Our own fig trees in North America are but sprawling parasitic trees, unable to stand alone. They are found only in the south of Florida, and therefore are generally unknown.

[Ill.u.s.tration: _See page 153_

FLOWERS AND FRUIT OF THE WILD BLACK CHERRY]

[Ill.u.s.tration: _See page 156_

A FRUITING BRANCH OF THE c.o.c.kSPUR THORN]

=The Golden Fig=

_Ficus aurea_, Nutt.

The golden fig climbs up other trees and strangles its host with its coiling stems and aerial roots. One far-famed specimen has grown and spread like a banyan tree, its trunk and head supported by secondary stems that have struck downward from the branches. Smooth as a beech in bark, crowned with glossy, beautiful foliage, like the rubber plants, this parasitic fig is a splendid tropical tree, but the host that supports all this luxuriance is sacrificed utterly. The little yellow figs that snuggle in the axils of the leaves turn purple, sweet, and juicy as they ripen. They are sometimes used in making preserves. An interesting characteristic of the wood of the golden fig is its wonderful lightness. Bulk for bulk, it is only one fourth as heavy as water.

THE PAPAWS

Two of the forty-eight genera of the tropical custard-apple family are represented by a solitary species each in the warmer parts of the United States. Important fruit and ornamental trees in the tropics of the Old World are included in this family, but their New-World representatives are not the most valuable. However, they have a sufficient number of family traits to look foreign and interesting among our more commonplace forest trees; and because their distribution is limited they are not generally recognized in gardens, where they are planted more for curiosity than for ornament.

=The Papaw=

_Asimina triloba_, Dunal.

The papaw has the family name, custard-apple, from its unusual fruit, whose flesh is soft and yellow, like custard. The shape suggests that of a banana. The fruits hang in cl.u.s.ters and their pulp is enclosed in thick dark brown skin, wrinkled, sometimes shapeless, three to five inches long. Dead ripe, the flesh becomes almost transparent, fragrant, sweet, rather insipid, surrounding flat, wrinkled seeds an inch long. The fruit is gathered and sold in local markets from forests of these papaws which grow under taller trees in the alluvial bottom lands of the Mississippi Valley. In summer the leaves are tropical-looking, having single blades eight to twelve inches long, four to five inches broad, on short, thick stalks. These leaves are set alternately upon the twig, and cl.u.s.ter in whorls on the ends of branches. The flowers appear with the leaves and would escape notice but for their abundance and the unusual color of their three large membranous petals. At first these axillary blossoms are as green as the leaves; gradually the dark pigment overcomes the green, and the color pa.s.ses through shades of brownish green to dark rich wine-red.

The full-grown foliage by midsummer has become very thin in texture, and lined with pale bloom. The tree throughout exhales a sickish, disagreeable odor. The fruit is improved in flavor by hanging until it gets a nip of frost.

This "wild banana tree" is the favorite fruit tree of the negroes in the Black Belt. Its hardiness is surprising. From the Southern states, it ranges north into Kansas, Michigan, New York, and New Jersey.

=The Melon Papaw=

_Carica Papaya_, Linn.

The melon papaw does not belong to the custard-apple family, but it grows in southern Florida and throughout the West Indies, and has the name of our little "wild banana tree," so it may as well have mention here, as it is the sole representative of the true Papaw family, and it is universally cultivated for its fruit in the warm regions of the world. By selection the fruit has been improved until it ranks as one of the most wholesome and important of all the fruits in the tropics.

In Florida the papaw grows on the rich hummocks along the Indian River, and on the West Coast southward from Bay Biscayne. It is very common on all the West Indian Islands. It grows like a palm, with tall stem crowned by huge simple leaves, one to two feet across, deeply lobed into three main divisions, and each lobe irregularly cut by narrow sinuses. The veins are very thick and yellow, and the hollow leaf-stalks lengthen to three or four feet. The bark of this tree is silvery white--a striking contrast with the l.u.s.trous head of foliage.

The flowers are waxy, tubular, fragrant, turning their yellow petals backward in a whorl. On fertile trees the fruits mature into great melons, sometimes as large as a man's head; but these are the cultivated varieties. Wild papaws rarely exceed four inches long, and usually they are smaller. When full grown the fruit turns to bright orange-yellow. The succulent pulp separates easily from the round seeds.

In the West Indies, the trees often branch and attain much greater size than in Florida, where fifteen feet is the maximum, in the wilds.

The leaves of this papaw contain, in their abundant sap, a solvent, _papain_, which has the property of destroying the connective tissue in meats. They are bruised by the natives and tough meat, wrapped closely in them, becomes tender in a few hours. The fruits are eaten raw and made into preserves. Negroes use the leaves also as a subst.i.tute for soap in the washing of clothes.

THE POND APPLES

The pond apple (_Anona glabra_, Linn.) is our only representative of its genus that reaches tree form and size, and it is the second of our native custard-apples. It comes to us _via_ the West Indies, and reaches no farther north than the swamps of southern Florida. It is a familiar tree on the Bahama Islands. Thirty to forty feet high, the broad head rises from a short trunk, less than two feet in diameter, but very thick compared with the wide-spreading, contorted branches and slender branchlets. It is often b.u.t.tressed at the base. The leaves are oval and pointed, rarely more than four inches long, bright green, leathery, paler on the lower surface, plain-margined. The flowers in April form pointed, triangular boxes by the touching of the tips of the yellowish white petals, whose inner surfaces near the base have a bright red spot.

The fruit, which ripens in November, is somewhat heart-shaped, four to six inches long, compound like a mulberry. The smooth custard-like flesh forms a luscious ma.s.s between the fibrous core and the surface, studded with the hard seeds. Fragrant and sweet, these wild pond apples have small merit as fruit. Little effort has been made to improve the species horticulturally. Its rival species in the West Indies have a tremendous lead which they are likely to keep.

=The Cherimoya=

_Anona Cherimolia_, Mill.

The cherimoya, native of the highlands of Central America, has long been cultivated, and its fruit has been cla.s.sed, with the pineapple and the mangosteen, as one of the three finest fruits in the world.

Certainly it deserves high rank among the fruits of the tropics. This also has been introduced into cultivation in southern Florida, but its culture has a.s.sumed much more importance in California, where it seems to feel quite at home.

The tree is a handsome one, with broad velvety bright green leaves, deciduous during the winter months. It grows wherever the orange is hardy, and its fruit, heart-shaped or oval, green or brown, is about the size of a navel orange. Conical protuberances cover the surface and enclose a ma.s.s of white, custard-like pulp, with the flavor of the pineapple, in which are imbedded twenty or thirty brown seeds. A taste for this tropical pond apple is as easily acquired as for the pineapple, which has become universally popular. Every garden in the Orange Belt should have a cherimoya tree for ornament and for its fruit.

THE PERSIMMONS

The persimmon tree of the Southern woods belongs to the ebony family, which contains some important fruit and lumber trees, chiefly confined to the genus _diospyros_, which has two representatives among the trees of North America. Doubtless a climate of longer summers would enable our persimmon trees to produce wood as hard as the ebony of commerce, whose black heart-wood and thick belt of soft yellow sap-wood are the products of five different tropical species of the genus--two from India, one from Africa, one from Malaysia and one from Mauritius. The beautiful, variegated wood called _coromandel_ is produced by a species of ebony that grows in Ceylon.

Fossil remains of persimmon trees are found in the miocene rocks of Greenland and Alaska, and in the later cretaceous beds uncovered in Nebraska. These prove that _diospyros_ once had a much wider range than now, extending through temperate to arctic regions, whereas now our two persimmons and the Chinese and j.a.panese species, are the only representatives outside the tropics.