The range of Prunus alleghaniensis is exceedingly limited. It is found in abundance only in a small territory in central Pennsylvania, being of most frequent occurrence in the barrens of northern Huntingdon County, extending from there north into Center County and northwestward over the Alleghany Mountains into Clearfield and Elk counties. It grows for the most part in elevated lands of the wildest character, being found on low, moist soils, on high and dry barrens and on limestone cliffs, reaching its greatest size in the last situation.
Specimens identified as Prunus alleghaniensis have been found in at least two places in Connecticut and the writer has just seen specimens of a closely allied form collected by W. F. Wight of the United States Department of Agriculture a few miles south of Houghton Lake, Roscommon County, Michigan.
This plum is not yet introduced into cultivation and it is doubtful if the wild fruits have sufficient merit to make an attempt at domestication promising. While the wild fruits are locally used for various culinary purposes it is so much inferior to other native plums, being almost uneatable unless cooked, that its cultivation would hardly warrant the effort. Arboretum specimens of the tree show it to be somewhat desirable as an ornamental, being a small, compact, upright plant, very floriferous, and bearing an abundance of rather attractive fruit.
14. PRUNUS SUBCORDATA Bentham
1. Bentham Pl. Hartweg. 308. 1848. 2. Torrey Pac. R. Rpt. 4:82. 1854. 3. Brewer and Watson Bot. Calif. 1:167. 1880 (in part). 4. Lemmon Pittonia 2:68. 1890. 5. Greene Fl. Francis 1:49. 1891. 6. Bailey Cornell Sta. Bul. 38:76. 1892. 7. Sargent Sil. N. Am. 4:31, 32, Pl. 154. 1892.
Tree small, rarely attaining a height of twenty-five feet, sometimes a shrub ten or twelve feet high and often a bush but three or four feet in height; trunk medium in length with a diameter of 8 to 12 inches; bark gray-brown and deeply fissured; branches stout and spreading; branchlets glabrous or pubescent, bright red becoming darker red and finally a dark-brown or gray; lenticels minute, whitish.
Leaves round-ovate, sub-cordate or truncate, or sometimes cuneate at the base; margins either sharply or obtusely serrate, sometimes doubly serrate; young leaves pubescent but at maturity nearly glabrous, somewhat coriaceous, dark green on the upper and pale green on the lower surface, with very conspicuous midribs and veins; stipules acute-lanceolate, caducous.
Flowers white, fading to rose, about an inch across; appearing before the leaves; usually borne in threes, often in pairs on short pubescent pedicels; calyx campanulate, with lobes pubescent on the outer and hairy on the inner surface; petals twice the length of the sepals, obovate, and contracted into short claws; filaments and ovary glabrous; style slender and funnel-shaped at the apex.
Fruit ripens in late summer or early autumn; roundish or oblong, about one inch in length, borne on a short, stout stem, dark red or purplish; flesh subacid, well-flavored, clinging to the flattish or turgid stone which varies greatly in size, pointed at both ends, crested on the ventral edge and grooved on the other.
Prunus subcordata, the Pacific or Western plum, is an inhabitant of the region east of the Coast Range from southern Oregon to central California. It is so rarely found on the seacoast as to have escaped the attention of the early botanists and remained unknown until the middle of the Nineteenth Century, when Hartweg, working in the interior of California, brought the plant to notice. This wild plum is not common except in the foothills of the Sierra Nevadas in northern California and southern Oregon, where it often forms thickets of small trees along streams, thriving in fresh, fertile, sandy soils, in canons, on hillsides or in the forests of yellow pine which are found in this region. Hammond[124] writes of it growing here as usually a small tree but often seen as a shrub from four to five feet high. Of the frequency of the occurrence he says: “It often sets the whole countryside ablaze in the autumn, with the abundance of its scarlet and crimson colors, mingled, of course, with red and yellow, and garnished with a sprinkling of green.” Sandberg[125] reports having collected Prunus subcordata as far north and east as Nez Perces County, northern Idaho, in the Craig Mountains at an altitude of about 2,900 feet, but this report is based on an error in determination, the specimen collected by Sandberg being clearly a European species. The tree and the fruit vary greatly according to the locality.