Oxalis, Tuberous-Rooted.— Law

Tuberous-rooted Wood-sorrel. Oca. Oxalis crenata.

Of the Tuberous-rooted Oxalis, there are two varieties, as follow:—

White-Rooted.

Oca blanca.

Stem two feet in length, branching, prostrate or trailing, the ends of the shoots erect; leaves trifoliate, yellowish-green, the leaflets inversely heart-shaped; flowers rather large, yellow,—the petals crenate or notched on the borders, and striped at their base with purple. The seeds are matured only in long and very favorable seasons. In its native state, the plant is perennial; but is cultivated and treated, like the common potato, as an annual.

Cultivation.—The tubers should be started in a hot-bed in March, and transplanted to the open ground in May, or as soon as the occurrence of settled warm weather. They thrive best in dry, light, and medium fertile soils, in warm situations; and should be planted in hills two feet and a half apart, or in drills two feet and a half apart, setting the plants or tubers an inch and a half deep, and fifteen or eighteen inches apart in the drills; treating, in all respects, as potatoes.

The tubers form late in the season; are white, roundish, or oblong, pointed at the union with the plant, and vary in size according to soil, locality, and season; seldom, however, exceeding an inch in diameter, or weighing above four ounces. The yield is comparatively small.

Use.—The tubers are used as potatoes. When cooked, the flesh is yellow, very dry and mealy, of the flavor of the potato, with a very slight acidity. The tender, succulent stalks and foliage are used as salad.

Oxalis, Red Tuberous-Rooted.

Oca colorada.

Plant similar in habit to the White Tuberous-rooted; but the branches, as well as the under surface of the leaves, are more or less stained with red. Tubers larger than those of the last named, roundish, tapering towards the connection with the plant, and furnished with numerous eyes in the manner of the common potato; skin smooth, purplish-red; flesh often three-colored,—the outer portion of the tuber carmine-red, the central part marbled, and the intermediate portion yellow,—the colors, when the root is divided transversely, appearing in concentric zones, or rings. The flesh contains but little farinaceous matter, and possesses a certain degree of acidity, which, to many palates, is not agreeable.

Propagated, and in all respects cultivated, like the White. Either of the varieties may also be grown from cuttings, which root readily.

According to a statement from the London Horticultural Society's Journal, the acidity may be converted into a sugary flavor by exposing the tubers to the action of the sun for eight or ten days,—a phenomenon which is analogous to what takes place in the ripening of most fruits. When treated in this form, the tubers lose all trace of acidity, and become as floury as the best descriptions of potatoes. If the action of the sun is continued for a long period, the tubers become of the consistence and sweet taste of figs. Mr. Thompson states that the disagreeable acid taste may also be removed by changing the water when they are three-quarters boiled.

The plants are tender, and are generally destroyed early in autumn by frost. The tubers must be taken up before freezing weather, packed in sand, and placed in a dry, warm cellar for the winter.

Deppe's Oxalis. Thomp. Vil.

Oxalis Deppei.

A perennial plant from Mexico, very distinct from the tuberous-rooted species before described. Stalk about one foot in height, smooth and branching; leaves four together, the leaflets wedge-shaped, pale yellowish-green, the upper surface marked by two brownish lines or stains in the form of two sides of a triangle; flowers terminal, of a carmine-rose or pink-red color, stained with green at the base of the petals. "The roots are fleshy, tapering, white, and semi-transparent, and furnished on the top of the crown with a mass of scaly bulbs, sometimes amounting to fifty in number, by means of which the plant can be easily propagated. When well grown, the roots are about four inches in length, and from one inch to one inch and a half in thickness."—Thomp.

Soil and Culture.—"This Oxalis requires a light, rich soil, mixed with decayed vegetable matter; and it prefers a southern aspect, provided the soil is not too dry.

"It may be raised from seed; but is generally propagated by planting the bulbs, which should be set the last of April or beginning of May, or when all danger of frost is over, six inches apart, in rows one foot asunder. The bulbs should be only just covered with soil; for thus they occupy a position, with regard to the surface, similar to that in which they are produced: and this seems indispensable, if fine roots are to be obtained.

"The stems have been observed to spring up from a considerable depth; but, in this case, tap-roots were not formed. During summer, the soil must be kept moist in dry weather; otherwise, when rain falls abundantly, the sudden accession of water to the roots occasions their splitting. The plants should be allowed to grow as long as there is no danger from frost; but, previous to this occurring, they should either be taken up or protected. If protected from frost by frames or otherwise, the roots will continue to increase in size till near November. When taken up, the roots should be divested of the numerous bulbs formed on their crowns, and then stored up for use in a cool, dry place, but secure from frost. A similar situation will be proper for the small bulbs; or they may be kept in dry sand till the season of planting."—Thomp.

The plant has been cultivated with the most complete success, with no especial preparation of the soil; merely planting the bulbs in shallow drills, the ground being dug and manured as for other kitchen-garden crops.

Use.—In a communication to the "Gardener's Chronicle," Prof. Morren gives the uses of the plant as follow:—

"The uses of the Oxalis are many. The young leaves are dressed like sorrel in soup, or as a vegetable. They have a fresh and agreeable acid, especially in spring. The flowers are excellent in salad, alone, or mixed with corn salad, endive of both kinds, red cabbage, beet-root, and even with the petals of the dahlia, which are delicious when thus employed. When served at table, the flowers, with their pink corolla, green calyx, yellow stripes, and small stamens, produce a fine effect. The roots are gently boiled with salt and water, after having been washed and slightly peeled. They are then eaten like asparagus in the Flemish fashion, with melted butter and the yolk of eggs. They are also served up like scorzonera and endive, with white sauce; and form, in whatever way they are dressed, a tender, succulent dish, easy to digest, agreeing with the most delicate stomach. The analogy of the root with salep indicates that its effect should be excellent on all constitutions."

"The bright rose-colored flowers being very ornamental, the plant is sometimes employed as an edging for walks."—Thomp.