The description of this species is based on both wild and cultivated material, and the variety Arkansas may be considered as a typical representative. Type specimens, deposited in the Economic Collection of the United States Department of Agriculture, were collected by W. F. Wight (flowers) at the New York State Experiment Station, Geneva, New York, No. 2721, May 15, 1909, and (foliage) at the Iowa Experiment Station, Ames, Iowa, No. 4178, September 15, 1909.
This species differs from Prunus angustifolia, with which it has long been confused, chiefly in being a much larger plant, a true tree while the other seldom reaches the size of a tree. It has coarser and less twiggy branches, shaggier bark and less red in the color of the young wood. The leaves are larger, thicker, more truly lanceolate in shape, less folded, a lighter green and less glossy. The flowers of the new species are larger, fewer in number, borne in less dense umbels which are not so nearly sessile as those of the older species and are borne on longer pedicels. The calyx-lobes are erect in this species and reflexed in Prunus angustifolia, strongly marked by marginal glands in Prunus munsoniana and eglandular in Prunus angustifolia. The fruits are larger and wholly plum-like in the newly made species and cherry-like in Prunus angustifolia. The stone is very plum-like in Prunus munsoniana but in the older species it might easily be mistaken for the pit of a cherry. The robust form is hardy as far north as Geneva, New York, at least, while the other species cannot be grown much north of Mason and Dixon’s line.
Of the varieties which certainly belong to this species by far the greatest number have originated under cultivation. There is herbarium material from uncultivated plants to show that this species is rather common in the northern part of Texas, in eastern Oklahoma and in parts of Missouri. It is a species forming dense thickets in its native habitat, where it is usually found in rather rich soils, with the older central specimens sometimes attaining a height of twenty to twenty-five feet and gradually diminishing in height to the edge of the thicket. When budded and grown in the orchard it forms a well-defined trunk and attains a height of twenty-five feet or more. The branches are little or not at all spinescent, bark of the stem in young specimens reddish or chestnut-brown, and usually rather smooth, becoming scaly and losing its reddish color with age, that of the young twigs usually chestnut-brown. Its natural range, though not yet definitely determined, probably extends from central Tennessee through northern Mississippi, northern Arkansas, central Missouri and southeastern Kansas to the valley of the Little Wichita River in northern Texas.
The Wild Goose varieties, now placed here, in the past have been considered hybrids more closely resembling Prunus hortulana than any other species. But Wild Goose and some other varieties of its group are not to be distinguished from Prunus munsoniana and beyond question belong in this species. The varieties in this division of Munsoniana are largely seedlings of Wild Goose, each variety possibly with a different male parent since Wild Goose seldom or never fruits unless cross-fertilized. Thus, of these plums, twelve are known seedlings of Wild Goose; seven others originated under cultivation; the origin of fourteen is not known and it is not certain that any beside Wild Goose came from wild plants. From such a record, and from the characters of the plants, it is probable that some of the Wild Goose varieties are horticultural hybrids, many of them from H. A. Terry of Iowa in whose work, with many varieties of several species, hybridity was the rule.
Horticulturally, this is the most important group of native plums for the South; it contains a greater number of cultivated varieties than any other native species excepting Prunus americana, no less than sixty sorts being listed in The Plums of New York, some of which are deservedly the best known of the native plums for either home or market use. For dessert or the kitchen they are particularly valuable, having a sprightly vinous flavor making them very pleasant flavored to eat out of hand or when cooked. Their bright colors, semi-transparent skins and well-turned forms make them very attractive in appearance. Considering the juiciness of most of the varieties, these plums ship and keep well. Unfortunately nearly all of the varieties of this species are clingstones. This group hybridizes more freely than any other of the plums and there are a great number of promising hybrids of which it is one of the parents. Of all plums, these are most in need of cross-pollination, some of the varieties being nearly or, as in the case of Wild Goose, wholly self-sterile. While these plums are especially valuable in the Southern States, some of them are desirable in the North as well, where all will grow at least as far north as central New York. Plums of this species are occasionally but not often used as stocks. Some recommend them for stocks for low or wet lands. The fact that Prunus munsoniana suckers very badly will probably preclude its use largely in propagating.
The leading varieties under cultivation of this species are Arkansas, Pottawattamie, Robinson, Newman, Wild Goose and Downing, all of which are described in full and illustrated in colors in The Plums of New York. The first four of these have in the past been referred by botanists and pomologists to Prunus angustifolia and the last two to Prunus hortulana.
20. PRUNUS MARITIMA Marshall
1. Marshall Arbust. Am. 112. 1785. 2. Wangenheim Amer. 103. 1787. 3. Michaux Fl. Bor. Am. 1:284. 1803. 4. Pursh Fl. Am. Sept. 332. 1814. 5. Nuttall Gen. N. Am. Pl. 1:302. 1818. 6. Elliott Sk. Bot. S. C. and Ga. 1:543. 1821. 7. Torrey and Gray Fl. N. Am. 1:408. 1840. 8. Torrey Fl. N. Y. 1:194. 1843. 9. Emerson Trees of Mass. 449. 1846. 10. Bailey Cornell Sta. Bul. 38:75, fig. No. 9. 1892. 11. Waugh Vt. Sta. An. Rpt. 12:234. 1899. 12. Bailey Cyc. Am. Hort. 1449, fig. 1901.
P. littoralis. 13. Bigelow Fl. Bost. Ed. 2:193. 1824.