60 BULLETIN 179, U. S. DEPARTMENT OF AGRICULTURE. 
Prunus Pennsyivanicoa IL, f, 
(Bird cherry. Pin cherry.) 
Prunus pennsylvanica L. f., 1781, Suppl. Pl., p. 252. 
Prunus persicifolia Desf., 1809, Hist. Arb., pt. 2, p. 205. 
Prunus montana Marsh., 1785, Arb. Amer., p. 118. 
Prunus lanceolata Willd., 1796, Berl. Baumz., p. 240. 
Mature leaves lanceolate (Pl. 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 Valley. 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- 
