P. Alleghaniénsis.
3. Prùnus Alleghaniénsis, Porter. (Alleghany Plum.) Leaves lanceolate to oblong-ovate, often long-acuminate, finely and sharply serrate, softly pubescent when young, smooth when old; fruit globose-ovoid, under ½ in., very dark purple, with a bloom; stone turgid, a shallow groove on one side and a broad, flat ridge on the other. A low, straggling bush, occasionally a tree, 3 to 15 ft. high. Mountains of Pennsylvania.
P. Chicàsa.
4. Prùnus Chicàsa, Michx. (Chicasaw Plum.) Leaves long, narrow, almost lanceolate, acute, finely serrate, thin. Flowers on short stalks. Fruit globular, ½ to 2/3 in. in diameter, thin-skinned, without bloom, yellowish-red, pleasant to taste. Stone globular, without sharp edges. A thorny shrub or small tree, 6 to 15 ft. high; wild in New Jersey, west and south, and often cultivated.
P. spinòsa.
5. Prùnus spinòsa, L. (Sloe. Blackthorn. Bullace Plum.) Leaves obovate-oblong to lance-oblong, sharply serrate, soon smooth; leafstalk smooth; fruit small, globular, black, with a bloom; the stone rounded, acute at one edge; flesh greenish, astringent. A low tree with thorny branches; it is becoming naturalized along roadsides and waste places; from Europe. Var. instititia (Bullace Plum) is less thorny, and has the leafstalk and lower side of the leaves pubescent.
P. doméstica.