XVIII

THE CLASSIFICATION OF PLUMS

FROM the standpoint of classification the plums are the most diverse and complicated of all our fruits. They have received more critical study in this country, however, than any other class of fruits, and as a proper result we have a much better system of classification for them than we have for apples or pears. The classification is more nearly natural, more scientific, and more useful.

All our American plum classification has been done on purely natural lines; at any rate, it has been planned on such lines. If it is unnatural or arbitrary at certain points it is only because it is seldom possible to see all the facts at once in any case so complex.

The most recent, as well as the most comprehensive, scheme of classification for plums, is that used in Waugh's "Plums and Plum Culture," and the general outline of this scheme will be followed here with the inter

* Waugh, "Plums and Plum Culture." Orange Judd Co., New York, 1900.

polation of only so much explanation as seems necessary to our present purpose.

It will be seen at once that in this scheme the classification is made to rest almost wholly on a botanical basis. The plums belong to a great many different botanical groups, and when we have given these their proper characterization and arrangement we have really made a classification for the cultivated varieties derived from those species and botanical varieties. This method was first effectively used in this country for plums by Professor L. H. Bailey.*

In the book on "Plums and Plum Culture" just mentioned the common European garden plums, derived from Prunus domestica, are subdivided considerably further than the purely botanical classification has usually been carried. Several natural types within this species are distinguished and classified, and this arrangement is also adopted in the following outline. At the same time the Japanese plums are similarly classified into several more or less distinct natural groups. This classification runs as follows:

*See especially Cornell Experiment Station Bulletin No. 38. 1892.

I. EUROPEAN GARDEN PLUMS (Prunus domestica).— Leaves large, coarse, rough, thick, usually pubescent beneath, coarsely serrate; flowers large, white, showy; fruit various; stone large, usually compressed and roughened. This group contains several important types, the most conspicuous being the following:

I. REINE CLAUDE TYPE.-Leaves comparatively large, broad, and flat, with very coarse serrations; fruit nearly spherical, green or tardily turning to a dull, creamy yellow, flesh rather firm or even hard, green, clinging to the stone. Bavay, Green Gage, McLaughlin, Imperial Gage, Jefferson, Lawrence, and many other varieties belong here.

2. DAME AUBERT TYPE.-Tree large; leaves large, coarse; fruit very large, oval, compressed, with more or less of a neck; flesh yellow. Yellow Egg (Magnum Bonum) and Golden Drop represent this type.

3. THE PRUNES.-Fruit medium to large, always oval or ellipsoid, usually with one side of the oval straighter than the other, compressed; color blue or purple; flesh mostly greenish-yellow, firm; stone usually free in a large cavity. Represented best by Fellenberg and German Prune.

medium to large,

4. THE PERDRIGONS.-Fruit spherical or oblate, sometimes distinctly depressed at the apex, usually with a deep suture, blue or purple; flesh greenish-yellow, rather firm. Not well represented in America, but typified in Goliath and Royal Tours.

5. DIAMOND TYPE.-Fruit mostly large, oval, very slightly compressed, always dark solid blue in color, with a heavy bloom which also appears to be blue;

flesh yellow, very firm, usually clinging to the stone. Well-known plums, such as Kingston, Quackenboss, Gueii, Arctic, etc.

6. BRADSHAW TYPE.-Fruit large, obovoid, pinkish or purplish, with thin skin and moderately soft, yellow, juicy flesh; quality excellent in all cases. Here belong Bradshaw, Pond, Sharp (Victoria), Field, Duane Purple, and a few others.

7. LOMBARD TYPE.-Closely resembling the foregoing, but differing in certain respects, more or less, as follows: Fruit usually smaller, more nearly oval, bluish, purplish, or pinkish-purple, more opaque in appearance than in the Bradshaw group; quality inferior to Bradshaw. In this group I would place Lombard, Communia Merunka, etc.

II. DAMSONS (Prunus domestica damascena).—Differ from Prunus domestica in being dwarfer, wood shorter jointed, leaves smaller, more sharply serrate; fruit small, oval, usually blue, very sour. Cluster Damson, French Damson, and several other named varieties are propagated in America.

III MYROBALANS (Prunus cerasifera).—Differs from Prunus domestica in having a more slender habit, smoother, shinier leaves, smaller flowers, softer, juicier fruit. The variety (possibly there are several different varieties) known as Cherry, or Early Cherry, is the best type of this group. De Caradeuc and Marianna are best known, but do not show pure Myrobalan characters.

IV. JAPANESE PLUMS (Prunus triflora).-Flowers usually densely fasicated; leaves smooth, glabrous, mostly flat, obovate or oblongovate, prominently

pointed and evenly and finely serrate; fruit with firm flesh and usually small, clinging stone. Represented by several rather diverse varieties, among which the following types are readily distinguishable:

1. BOTAN TYPE.-Fruit roundish but always more or less pointed; flesh yellow; skin mostly heavily sprinkled or splashed with red, never solid red or yellow. Abundance, Burbank, Chabot.

2. RED JUNE TYPE.-Fruit usually small to medium, frequently oblong, compressed; color solid red or yellow; flesh firm, meaty, dry; flavor flat; quality poor. Red June, Kerr, Willard, Ogon.

3. SATSUMA TYPE.-Fruit large, round, pointed, dark red; flesh firm, red. Satsuma.

4. KELSEY TYPE.-Tree tender; fruit large, oval, flattened; yellow skin and flesh. Kelsey. This type is closely related to the Red June type, and perhaps the two ought to be grouped together.

5. HALE TYPE.—Tree very vigorous, upright grower, coming tardily into bearing; fruit medium to large, round or round-oblate, with a comparatively long stem, transparent yellowish skin (very different from the opaque tomato yellow of Ogon), considerably washed and splashed with red or purplish red; flesh rather soft and juicy. Hale, October Purple.

6. BERGER TYPE.-Fruit small, somewhat cherrylike, usually round-oblate, sometimes slightly compressed, usually with a distinct suture; color yellow or red; flesh hard and dry; quality generally poor; ripening very early. Berger, Earliest of All, Engre.

V. GONZALES GROUP (Prunus triflora robusta).--A comparatively homogeneous group, made up of hy