A century ago the fruit-growing of the country was largely in the hands of amateurs and patrons of horticulture. Many varieties of plums must have been introduced by these lovers of plants. Among such growers of fruit was William Hamilton of Philadelphia, who introduced the Lombardy poplar in 1784, and who in 1800 was growing all the plants and fruits procurable in Europe. Ezekiel Henry Derby of Salem, Massachusetts, one of the founders of the Massachusetts Society for Promoting Agriculture, grew many choice foreign plants in his garden, greenhouse, orchard and arboretum, and attained well merited fame as a horticulturist.[29] Dr. David Hosack, botanist and founder in 1801 of the Elgin Botanic Gardens in what is now New York City, was one of the most distinguished patrons of pomology of his time and grew many new fruits and plants from Europe, afterwards placing them in the hands of the horticulturists of the country.[30]
These are but a very few of the many men who, having wealth and leisure, were engaged in growing fruits and plants as an avocation but were adding greatly to the material and knowledge of those to whom fruit-growing was a vocation. As a further example of how much these men contributed to horticulture, a purchase made by a member of the New York Horticultural Society may be cited. At a meeting of the Society held in July, 1822, he mentioned a list of fruit trees which he had purchased in Europe, comprising 784 varieties.[31]
The period during which American pomology may be said to have been in the hands of wealthy amateurs began shortly after the close of the Revolution and did not fully merge into that of commercial pomology until the close of the Civil War. Soon after the beginning of the Nineteenth Century, horticulture, in fact all agriculture, was greatly stimulated by the publication of agricultural books[32] and magazines[33] and the formation of agricultural and horticultural societies.[34] The frequency of the names of these publications of a century ago in The Plums of New York is an indication of the contributions they made to the culture of the plum.
Having briefly outlined the history of the Domestica plums, we come now to a discussion of what we have under cultivation in this fruit. The Domestica plums, 950 or more mentioned in this text, may be divided into several more or less distinct pomological groups. These groups are of interest because in their history the evolution of the plum under consideration is further developed; because such groups are serviceable to plum-growers, as each division has adaptation for particular conditions or particular purposes; and because of their value to the breeder of plums since the largest and best differentiated groups, as a rule, have their characters most strongly fixed and may be relied upon to best transmit them to their offspring.
Groups of plums in pomology are founded for most part upon the characters of the fruit since these are most readily recognized by fruit-growers. Yet whenever possible, leaf, flower and tree-characters are considered. The name given is usually that of the best known variety in the group though in some of the divisions the name is that of the variety which seems to be intermediate in character between the other members of the group.
The groups of plums recognized by pomologists were far more distinct as we go back in their history. For, in the past, each fruit-growing region had a pomology of its own in which the varieties of any fruit were few and similar, constituting but one, or at most a very few types. The various groups of plums, therefore, largely represent distinct plum-growing regions. With the increase in intercourse between the countries of the world, cultivated plums have been taken from place to place and as new varieties have originated, often from crosses between varieties, the dividing lines between divisions have been more or less broken down. The first of the groups to be considered is:—
The Reine Claude or Green Gage Plums.—This group is so distinctive in several characters that some botanists and pomologists separate it from other Domestica plums as a sub-species or species[35] and in common parlance its numerous varieties are very generally grouped together as “green gages” as if it were quite a distinct fruit from other plums. It comprises a considerable number of relatively small, round, mostly green or golden plums of so high quality as to make them standards in this respect for all plums. The Reine Claude is one of the oldest types of which there are records. Its varieties reproduce themselves without much variation from seed though there are a few sorts, possibly crosses with some other group, which are doubtfully referred to the Reine Claudes. The later history of these plums is most interesting and is reliable, for the group is recognized and discussed by almost every European or American pomologist who has written in three centuries.[36] The early history is not so well known.
Where the Reine Claude plums originated no one knows. Koch[37] says he has eaten wild plums in the Trans-Caucasian region, which must be recorded with the Reine Claudes, but on the next page he advances the theory that the group is a hybrid between Prunus domestica and Prunus insititia. Schneider[38] puts the Reine Claudes in Prunus insititia. The group seems to be a connecting link between the two species named above, having so many characters in common with each that it is exceedingly difficult to choose between the two as possible parent species. Prunus domestica probably originated in the Caucasian or Caspian region, and it is likely, as Koch suggests, that the Reine Claudes were brought from there. This is substantiated by the early pomologists, who say these plums came originally from Armenia and were known as the Armenian plums, coming eventually by the way of Greece to Italy. If this statement of its origin be true, Columella[39] knew the fruit, for he says:
—“then are the wicker baskets cramm’d
With Damask and Armenian and Wax plums.”