Genus 36. PRÙNUS.
Trees or shrubs with simple, alternate, deciduous, usually serrate, stipulate leaves, without lobes. The stems produce gum when injured. Foliage and nuts have flavor of peach-leaves. Flowers conspicuous, usually white, or light pink, often in clusters, peach-blossom-shaped; in early spring. Fruit in size from pea to peach, a rounded drupe with one stony-coated seed.
| * Drupe large, soft velvety on the surface; stone rough (Peach, Apricot) | 1. | |||
| * Drupe medium, covered with a bloom; stone smooth, flattened (Plums). (A.) | ||||
| A. Usually thorny; wild, rarely cultivated. (B.) | ||||
| B. Leaves acuminate | 2, 3. | |||
| B. Leaves not acuminate | 4, 5. | |||
| A. Not thorny; cultivated | 6. | |||
| * Drupe medium to small, smooth, without bloom (Cherries). (C.) | ||||
| C. Drupes clustered in umbels, ½-1 in. in diameter. (D.) | ||||
| D. Small cultivated tree; drupe globose, rather large, very sour | 9. | |||
| D. Large cultivated tree; drupe large, somewhat pitted at the stem | 8. | |||
| D. Rather small, native tree; drupe small, flesh thin | 7. | |||
| C. Drupes clustered in racemes, 1/8 - 1/3 in. in diameter. (E.) | ||||
| E. Tall shrubs rather than trees; racemes short | 11. | |||
| E. Trees; racemes quite elongated. (F.) | ||||
| F. Stone of fruit somewhat roughened | 12. | |||
| F. Stone smooth | 10. | |||
P. Pérsica.
1. Prùnus Pérsica, L. (Common Peach.) Leaves lanceolate, serrate. Flowers rose-colored, nearly sessile, very early in bloom. Fruit clothed with velvety down, large; stone rough-wrinkled. A small tree, 15 to 30 ft. high, cultivated in numberless varieties for its fruit. Var. lævis (Nectarine) has smooth-skinned fruit.
P. Americàna.
2. Prùnus Americàna, Marsh. (Wild Yellow or Red Plum.) Leaves ovate or somewhat obovate, conspicuously pointed, coarsely or doubly serrate, very veiny, smooth when mature. Fruit with little or no bloom, ½ to 1 in. in diameter, yellow, orange, or red; skin tough and bitter. Stone with two sharp edges. A small, thorny tree, 8 to 20 ft. high, common in woodlands and on river-banks. Many improved varieties, some thornless, are in cultivation. Wood reddish color.
