60 BULLETIN 179^ U. S. DEPARTMENT OF AGEICULTUEE. 



Prunus Pjennsylvanica L. f . 

 (Bird cherry. Pin cherry.) 



Prunus pennsylvanica L. f., 1781, Suppl. PL, p. 252. 

 Prunus persidfolia Desf., 1809, Hist. Arb., pt. 2, p. 205. 

 Prunus montana Marsh., 1785, Arb. Amer., p. 113. 

 Prunus lanceolata Willd., 1796, Berl. Baumz., p. 240. 



Mature leaves lanceolate (PI. VI, fig. 1), oblong-lanceolate or 

 oval-lanceolate, narrowed or rounded at the base, acuminate toward 

 the apex, the young leaves at first oval or ovate, sometimes slightly 

 falcate, 6 to 12 cm. long, 1.5 to 4 cm. broad, the margin finely serrate 

 with glandular incurved teeth, entirely glabrous or slightly pubes- 

 cent below along the prominent midvein and the lateral veins near 

 their junction with the midvein, or, when young, sometimes spar- 

 ingly and inconspicuously pubescent on the lower surface; stipules 

 linear and glandular serrate. Flowers 9 to 12 mm. broad, appearing 

 with the half-grown leaves from early in May to the last of June in 

 the northern part of its range, 3 to 7 together in umbellike or some- 

 times corymblike clusters, the latter sessile or sometimes short 

 stalked; pedicels 12 to 18 mm. long, slender and glabrous; calyx 

 obconic, glabrous, the tube 2.5 to 3 mm. long, the oblong or ovate- 

 oblong obtuse lobes about 2 mm. long, eglandular, reflexed at anthe- 

 sis; petals about 5 mm. long, oblong-orbicular and abruptly con- 

 tracted to a short claw, sometimes slightly pubescent on the outer 

 surface near the base. Fruit globular, with thin flesh, 6 to 7 mm. in 

 diameter, red, ripening from the middle of July to the first of Sep- 

 tember; stone oblong-oval to roundish oval (PL XII, figs. 35 to 37), 

 5 to 6 mm. long, with a thickened obscurely grooved ridge on the 

 ventral side. 



Prunus pennsylvanica sometimes attains a height of 30 or 35 feet^ 

 often sprouting from the roots and forming thickets. The bark of 

 the older trunks is somewhat scaly, while that of the smaller trunks 

 and branches is rather smooth and reddish brown, marked with 

 prominent horizontal bands of lenticels. It separates in horizontal 

 papery strips, resembling the birch in this respect. The bark of the 

 young twigs is reddish and somewhat lustrous. 



Prunus pennsylvanica ranges (fig. 4) from Newfoundland and New 

 England westward through the valley of the St. Lawrence, Pennsyl- 

 vania, northern Ohio, and northern Indiana to the Black Hills and 

 the eastern slopes of the Rocky Mountains, where it passes into the 

 subspecies. It apparently does not occur north of Lake Huron, but 

 extends northwestward from the western end of Lake Superior to 

 the Winnipeg VaUey. It is reported to extend to the shores of Hud- 

 son Bay (66, p. 36), but no specimens have been seen from that 

 region. It is common in the Alleghenies from Pennsylvania south- 



