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, pi.; Otis, 158. P. 

 Persica. Blakeslee & Jarvis, 332, 334, 341, 512, pi.; Bose- 

 mann, 74; Price, Bulletin 39, Texas Agr. Exper. Station, 828, 

 f. 13-15; Schneider, f. 183; Shirasawa, 253. P. pseudocerasus. 

 Shirasawa, 256, pi. 6. P. pumila. Schneider, f. 186. P. sero- 

 tina. Blakeslee & Jarvis, 341, 496, pi.; Brendel, pi. 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, pi. 6. P. tri- 

 flora. Blakeslee & Jarvis, 508, pi. P. triloba. Schneider, f. 

 185. P. virginiana. Blakeslee & Jarvis, 341, 498, pi.; 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. 



