BOTANY OF LA SALLE COUNTY. 69 



Order 33. ROSACEAE. Roses. 



Trees, shrubs or herbs with regular flowers 

 numerous stamens inserted on the calyx, 1 to 5 

 pistils and leaves with stipules. 



PRUNUS. Plum. Cherry. Trees of moderate size 

 often thorny with white flowers in cymes and a 

 fruit enclosing 1 a flattened smoothish stone. 



P. Americana. Thorny, 8 to 20 ft.; leaves ovate 

 or obovate, acute, doubly serrate, very veiny, 

 smooth; fruit roundish, Y. Or. or R.; M. Banks 

 of streams. 



P. Pennsylvania. Wild Red Cherry, a small 

 tree, Leaves oblong-, acuminate, finely serrate, 

 shining' green; W., M. Fruit round, red, small, 

 on long 1 pedicels. 15 to 25 ft. A handsome, sym- 

 metrical tree. 



P. Virg-iniana. Choke Cherry. Leaves oval, ob- 

 long- or obovate, abruptly pointed, sharply, often 

 doubly serrate, thin; flowers with roundish 

 petals in short, close racemes, W. Fruit red 

 turning- to dark, crimson; until fully ripe having- 

 a very puckery taste. 6 to 8 ft.; bark grayish. 

 River banks. 



P. serotina. Wild Cherry. Wild Black Cherry. 

 A larg-e fine tree. Leaves oblong-, lanceolate, 

 taper pointed, serrate, thick, g-lossy above; 

 flowers small in long- racemes, petals obovate. 

 W., M., fruit Bl., Aug\, 50 to 70 ft. Wood 

 fine grained, valuable. 

 SPIRAEA. P. Meadow Sweet. Spiraea. 



S. opulifolia. (Neillia opulifolia.) A many stemed 

 shrub with recurved, grayish branches, round, 

 somewhat 3 lobed, heart shaped leaves; flowers 

 in corymbs. W., pods short, Old bark loose 

 in thin layers on stem. 4 to 10 ft. 



