The flowers of the coffee tree are greenish purple and incon spicuous, borne in erect racemes or loose panicles on separate trees. The pistillate trees are burdened with their clumsy pods in the autumn. They are so heavy as to inflict a painful bruise if they strike a person in falling. The pioneers of Kentucky made out of the seeds a beverage to take the place of coffee. We may well wonder how they ever ground these adamantine beans, and how they ever drank a beverage as bitter as it must have been.
4. Genus ROBINIA, Linn.
Trees of the genus Robinia have slender, angled branchlets usually set with paired prickles which are the spiny stipules of !eaves, past or present. The leaves are once compound, and have the habit of closing and drooping when night comes or when rain begins to fall. The pea-like blossoms are in showy clusters; the pods are thin valved, opening when ripe, but slow to fall from the tree.
Four species belong to the United States; of these three are arbourescent. Three more occur in Mexico. Other countries are without native species, so they borrow of us. Streets, parks and gardens, in various parts of Europe, are planted with our black locust. The genus contains one of the good lumber trees of this country, and some of our handsomest flowering trees.
Locust, Yellow Locust, Black Locust (Robinia P seuda cacia, Linn.)—A tall, slender tree, 4o to 8o feet high, with erect branches forming an oblong head. Bark rough, dark grey, deeply furrowed; twigs smooth, silvery, downy, becoming reddish brown. Wood brownish yellow, hard, coarse grained, heavy, strong, very durable in contact with soil. Buds pointed, silky, all but tip hidden. Leaves 8 to 14 inches long, alternate, odd-pinnate of 9 to 19 leaflets, silvery, downy when young, later, pale beneath, dark green above, turning yellow in early autumn. Stipules in pairs, spiny, persistent, becoming thorny. Flowers, May to June, in axillary, drooping racemes, white, fragrant, pea-like, of good size. Fruit thin, brown, smooth, 4 to 8-seeded pods, hanging on through the winter. Preferred habitat, gravelly soil on mountain slopes. Distribution, Pennsylvania to Georgia, west to Iowa and Oklahoma. Naturalised in New York, New England, and west of Rocky Mountains. Uses: Planted as a shade and ornamental tree. Wood exceptionally durable and strong. Used in ship
building, for mill cogs, posts, ties, wagon hubs and spokes, and especially for tree nails. Excellent fuel. Bark has tonic properties.
The locust is a beautiful tree in its youth, and being a rapid grower, becomes sturdy and spreading in a few years. But its twigs and branches are brittle, the wind breaks them, and the symmetry of the crown is soon lost. An old locust is a dead, "craggly-looking object for half the year. Coarse, ragged bark covers trunk and larger branches. The twigs show no sign of buds. These trees have a fashion of hiding their winter buds in the wood of the twig, as the sumachs do. The pods hang on all winter, chattering in the wind, and calling attention to the hope lessly untidy appearance of the tree as a feature of the landscape.
Whatever may be urged against it—and it surely has its faults—the locust redeems itself in the late spring. The delicate leaf spray is silvery as it unfolds, changing to dark green as the masses of white fragrant bloom are shaken out. From a little distance the green leaves are obscured by the flowers; it is as if a white cloud rested on the treetop, heavy with perfume and alive with bees. One rarely sees, even in spring, a sight more beautiful. It is the supreme moment in the life of this tree.
A very interesting habit of the locust is the folding of its leaflets and the drooping of its leaves on rainy days and on the approach of evening. The sensitive plant, a near relative, shrinks away and folds its leaves whenever it is touched. It is believed the locust's habit of "cuddling down" avoids excessive loss of moisture and heat. Parkinson, writing of the tree in 1640, noted "each leaf foulding itself double every evening upon Sunne setting, and opening again upon the rising." Some years before, the cultivation of locusts had been introduced in Europe by Vespasian Robin, whose name the genus bears. Great plans were made a century ago for the growing of these trees to supply the British Navy with shipbuilding timbers. The plan never reached the magnitude its promoters desired; yet the locust is to be met with more often in European gardens and forests than any other American tree. The leaves are a common forage for cattle.