ROSACEAE. 129 
160. P. Padus. Bosemann, 53; Fant, 20, f. 15; Schneider, f. 
184; Ward, 1:241, f. 125; Willkomm, 3, 38, f. 58. P. pennsyl- 
vanica. Blakeslee & Jarvis, 332, 341, 500, pl.; Otis, 158. P. 
Persica. Blakeslee & Jarvis, 332, 334, 341, 512, pl.; Bose- 
mann, 74; Price, Bulletin 39, Texas Agr. Exper. Station, 828, 
f. 13-15; Schneider, f. 183; Shirasawa, 253. P. pseudocerasus. 
Shirasawa, 256, pl. 6. P. pumila. Schneider, f. 186. P. sero- 
tina. Blakeslee & Jarvis, 341, 496, pl.; Brendel, pl. 3; Hitch- 
cock (1), 5; Otis, 154; Schaffner & Tyler, Ohio Naturalist, 
1:31; Schneider, f. 48, 183. P. spinosa. Bosemann, 53; Fant, 
22, f. 17; Schneider, f. 96, 186; Ward, 1:245, f. 127; Willkomm, 
4, 9, 40, f. 64. P. tomentosa. Shirasawa, 253, pl. 6. P. tri- 
flora. Blakeslee & Jarvis, 508, pl. P. triloba. Schneider, f. 
185. P. virginiana. Blakeslee & Jarvis, 341, 498, pl.; Hitch- 
cock (3), 14; Otis, 156. 
1. Evergreen: leaves entire or slightly toothed. 2. 
Deciduous. 3. 
2. Tree: leaves rather lanceolate, about 3x8 cm. 
(American cherry laurel). P. caroliniana. 
Subarborescent: leaves rather ovate, about 4x10 cm. 
(European cherry laurel). P. Laurocerasus. 
3. End-bud present. 4. 
End-bud deciduous. (Plums). 14. 
4. Twigs green or red. 5. 
Twigs brown or gray. 6. 
5. Buds hairy: tree. (Peach). (1). P. Persica. 
Buds glabrous: twigs slender: low shrubs. 
(Flowering almond). P. nana. 
6. Stipules persistent or broken above the base: shrub. 7. 
Stipules deciduous from the leaf-cushion. 8. 
7. Loosely hairy: stipules setaceous. (2). P. tomentosa. 
Glabrate or puberulent: stipules deeply fimbriate. 
P. triloba. 
8. Twigs more or less velvety. 9. 
Twigs glabrous. 10. 
