68 ROSACEAE 



7. Leaves green. 8. 



Leaves purple. P. cerasifera Pissardii. 



8. Flowers single. P. cerasifera. 

 Flowers double. P. cerasifera Plantieriensis: 



9. Buds red-brown, short (3-4 mm.). P. americana. 

 Buds blackish or gray, long (4-5 mm.). P. nigra. 



10. Buds before branching round-ovoid. 11. 

 Buds distinctly elongated. 21. 



11. Fruit hairy, breaking away without a stalk. 



(Amygdalus). 12. 

 Fruit glabrous or with a stalk. 17. 



12. Fruit with dry flesh, splitting. (Almond). 14. 

 Fruit succulent. (Peach). 13. 



13. Flowers single. P. Persica. 

 Flowers double. P. Persica plena. 



14. Tree, with green or red twigs. P. communis. 

 Shrubs. 15. 



15. Bud-scales ciliate: leaves broad, often 3-lobed. P. triloba. 

 Bud-scales not ciliate: leaves narrow. 16. 



16. Flowers single. P. japonica. 

 Flowers double. P. japonica plena. 



17. Fruit breaking from stalk. (Nectarine). P. Persica laevis. 

 Fruit with stalk: stone smooth. (Cherries). 18. 



18. Leaves whitish, revolute: twigs often red. 19. 

 Leaves green, not revolute. 20. 



19. Leaves ascending. (Sand cherry).. P. pumila. 

 Leaves spreading. P. Besseyi. 



20. Leaves nearly as broad as long, glabrous. P. Mahaleb. 

 Leaves equally broad: villous. P. tomentosa. 

 Leaves distinctly elongated. P. pennsylvanica. 



21. Flowers and fruit in umbels. (Cherries). 22. 

 Flowers and fruit in racemes. (Bird-cherries). 24. 



22. Trees percurrent: leaves 1 rather drooping. 23. 



Tree deliquescent: leaves spreading. P. Cerasus. 



23. Young leaves hairy. (Sweet cherry). P. avium. 

 Young leaves glabrate. P. serrulata. 



