The peaches of New York

by U. P. Hedrick

PRUNUS DAVIDIANA (Carrière) Franchet

P. Davidiana Franchet Nouv. Arch. Mus. Paris ser. 2, V:255 (Pl. David. 1:103). 1883.

Persica Davidiana Carrière Rev. Hort. 74. 1872.

Prunus Persica var Davidiana Maximowicz Bul. Acad. Sci. St. Petersbourg 29:81; Mel. Biol. 11:667. 1883.

Tree attaining a height of twenty-five feet on the Station grounds, vigorous, upright, with slight spreading tendency, dense-topped, hardy in tree but not in flower-bud, unproductive; trunk stocky; branches thick, smooth, bronze-colored; branchlets slender—inclined to rebranch, long, with rather short internodes, ash-gray mingled toward the base with dark brown, glabrous, with inconspicuous, small, slightly raised lenticels.

Leaves five and one-half inches long, one and one-eighth inches wide, curled downward, oval to obovate-lanceolate, thick; upper surface smooth, dull, dark green; lower surface grayish-green; margin coarsely serrate, tipped with reddish-brown glands; petiole five-eighths inch long, glandless or with one or two small, globose, reddish glands at the base of the leaf.

Flower-buds tender, small, pointed, plump, appressed, brownish-red; flowers appear very early, a few days earlier than Prunus tomentosa, usually on short spurs; blossoms one and five-eighths inches across, whitish, tinged with pale pink near the margins, well distributed, usually singly; pedicels short, glabrous, green; calyx-tube reddish-green, orange-colored within, obconic, glabrous; calyx-lobes long, narrow, glabrous within and without; petals widely spaced, oval, shallowly dentate, tapering to long, white claws; filaments shorter than the petals; pistil red, heavily pubescent at the ovary, as long as the stamens.

Fruit less than one inch in diameter, nearly spherical; cavity medium in width and depth; suture shallow, deeper toward the base; apex mucronate; color grayish-white turning yellow at maturity; pubescence downy; skin wrinkles and roughens before maturity and soon decays; flesh very thin, rather dry, tasteless and insipid, lacking almost entirely the flavor of the peach; not edible; stone separates from the pulp readily even before ripe, nearly spherical, plump, very blunt at base and apex; surfaces deeply pitted.

Father David's peach, Prunus davidiana, has been grown in Europe since 1865 as an ornamental, seeds of it having been sent from China to France in that year by Father David, a missionary traveler.[175] The species is described as flowering in America in the Arnold Arboretum as early as 1888,[176] seeds from which the trees grew having been sent from China. Some ten or twelve years ago the species was distributed by the United States Department of Agriculture, trees being received at this Station in the spring of 1906. Meanwhile, agricultural explorers representing this country in China have discovered that the species is much used by the Chinese as a stock upon which to work other species of Prunus. Whereupon, new distributions were made through seeds and plants to nearly every fruit-growing state in the Union. We are, therefore, now able to speak of the behavior of the Davidiana peach in America with some degree of confidence as to its future as a stock for peaches. But, first, a word as to its habitat and uses in China.

The several importations of seeds recorded by the United States Department of Agriculture seem all to have been made from the province of Chili in China and from the cities of Pekin and Tientsin in the neighborhood of which the tree is commonly found wild. According to Bretschneider,[177] the species was first discovered by Bunge near Peking in 1831 who took it to be an almond. The same authority says that Father David's seeds came from wild trees growing in the mountains near Jehol, and that the species is much cultivated in the gardens of Peking, there being two varieties, one with rose-colored and the other with white flowers. At the time of its introduction into Europe, it was considered, by some, the wild form of the cultivated peach. The fruit of David's peach is not edible and peach-growers would have but passing interest in the species as a very attractive ornamental were it not for the fact that it is a common and most valuable stock, used for centuries in China for several of the stone-fruits.

It is, then, with a view to its fitness as a stock that the Davidiana peach must be discussed. Its characters in several respects indicate that it may make an invaluable stock in America as it has long been in China. For this purpose it seems possible to use it equally well for several stone-fruits.

As it grows on the Station grounds the most experienced fruit-grower cannot guess whether Prunus davidiana is a peach, nectarine, almond, apricot or plum. As we shall show later, too, it hybridizes with several other species of its genus. Its similarities to all of these stone-fruits give a clue to its value as a stock—it may be used for all. It is the commonest stock for all of these fruits in parts of China and is sometimes used for the cherry as well. It is reported by the United States Department of Agriculture[178] to have been tried in commercial plantings of peaches, plums, apricots and almonds in California and Texas and for all is "unusually promising."

PRUNUS DAVIDIANA

The trees are vigorous, healthy, hardy, and resistant to drouth. Consorted with any stone-fruit it should impart these qualities in some degree to the resulting tree. On the Station grounds, Prunus davidiana is growing with vigor and health despite the fact that in the ten years of its existence here we have had all but record-breaking extremes of cold, heat, drouth and rain—a decade long to be noted for its extremes of weather. It seems to stand the heat of Texas, and in Minnesota has withstood cold as low as forty degrees below zero, a temperature which kills commercial varieties to the ground. It cannot be fruited, however, in cold climates as its buds swell quickly with rises of temperature and succumb to subsequent cold; neither will it fruit in regions of late frost since it is one of the earliest species in the genus Prunus to flower. In Texas and southern California, according to the United States Department of Agriculture, it is proving resistant to drouth and in the latter region to alkali as well. In very dry and exposed places, it is said to lose its tree-characters and to become a thrifty shrub.

Present nursery practices in growing peaches are unsatisfactory in the extreme. More and more, pits from canneries are being planted for stocks. The pits come from a great diversity of varieties and the resulting seedlings are variable in vigor, health, size and capacity to take the bud. Should no unsurmountable weaknesses appear in Prunus davidiana it is almost certain that its seedlings will be more satisfactory as stocks for the peach than those from either cannery pits or from pits grown on southern wild trees. The trees do not fruit well in this climate, even when buds and flowers escape the cold, possibly because of infertility of bloom, and for this reason, the chief objection so far, some favorable region would have to be discovered in which to grow the pits.

As one might suspect from its similarities to the several stone-fruits, Prunus davidiana gives promise of being a go-between in hybridization. I. V. Mijurin, a noted Russian hybridist of Kozloo, Russia, has crossed the Davidiana peach and the dwarf almond, Prunus nana, with the idea of getting a hardy fruit for central Russia. The resulting offspring, according to Mr. F. N. Meyer,[179] looks in tree like the peach-parent but the fruit is more like that of the almond-parent. The fruit of the hybrid is inedible but the plant is a handsome ornamental. Mr. Mijurin states that while neither of the two parents will hybridize with the common peach, this hybrid does. Prunus davidiana, then, like the Sand Cherry of the Western Plains, may prove to be a valuable go-between in hybridizing species of Prunus.

The fruit has no comestible value. It is small, less than an inch in diameter, nearly round, very downy, yellow at maturity, with thin, dry, tasteless flesh which parts readily from the stone even before fully ripe. As if to complete its worthlessness as an edible product, it begins to shrivel as maturity approaches and soon decays. In fruit, even more than in tree, it is an intermediate between the peach and the almond.

A word must be said as to the merits of Prunus davidiana as an ornamental. It is the first harbinger of spring in the great family to which it belongs, bursting into a profusion of white or pinkish flowers with the approach of warm weather even before forsythias are in flower. Its thickly set, erect branchlets are wands of pinkish-white two feet in length, making a handsome tree and furnishing beautiful cut-flowers. If grown for its flowers, however, one must be content in northern climates to have it in bloom only about one season out of three but even so it repays culture. The Chinese cultivate dwarf specimens, possibly a dwarf form, for winter-flowering and the plant, it would seem, would readily lend itself to winter-forcing in American floriculture. The tree, quite aside from its flowers, is handsome at all times. A form with pure white flowers is a very desirable ornamental.[180] On the Station grounds this white-flowering peach has a fastigiate habit of growth and resembles somewhat a small Lombardy poplar.