G.36J CLASSIFICATION AND DESCRIPTION 97 



ORDER XVIII. ROSACES. (Ross FAMILY.) 



A large and very useful order of trees, shrubs, and 

 herbs of temperate regions. 



GENUS 36. PRUNUS. 



Trees or shrubs with simple, alternate, deciduous, 

 usually serrate, stipulate leaves, without lobes. The 

 stems produce gum when injured. Foliage and nuts 

 have flavor of peach-leaves. Flowers conspicuous, usually 

 white, or light pink, often in clusters, peach-blossom- 

 shaped ; in early spring. Fruit in size from pea to peach, 

 a rounded drupe with one stony-coated seed. 



* Drupe large, soft velvety on the surface ; stone rough (Peach, 

 Apricot) 1. 



* Drupe medium, covered with a bloom; stone smooth, flattened 



(Plums). (A.) 



A. Usually thorny ; wild, rarely cultivated. (B. ) 



B. Leaves acuminate 2, 3. 



B. Leaves not acuminate 4, 5. 



A. Not thorny ; cultivated 6. 



* Drupe medium to small, smooth, without bloom (Cherries). (C.) 



C. Drupes clustered in umbels, J^-l in. in diameter. (D.) 

 D. Small cultivated tree ; drupe globose, rather large, very 



sour 9. 



D. Large cultivated tree ; drupe large, somewhat pitted at the 

 stem 8. 



D. Bather small, native tree ; drupe small, flesh thin 7. 



C. Drupes clustered in racemes, ^-^ in. in diameter. (E.) 



E. Tall shrubs rather than trees ; racemes short 11. 



E. Trees; racemes quite elongated. (F.) 



F. Stone of fruit somewhat roughened . . 12. 

 F. Stone smooth 10. 



1. Prunus P6rsica, L. (COMMON PEACH.) 

 Leaves lanceolate, serrate. Flowers rose-col- 

 ored, nearly sessile, very early in bloom. Fruit 

 clothed with velvety down, large ; stone rough- 

 wrinkled. A small tree, 15 to 30 ft. high, culti- 

 vated in numberless varieties for its fruit. Var. 

 Isevis (Nectarine) has smooth-skinned fruit. 

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