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.