52 Rosacese. 



ORDER 23. — Rosacese. 



Calyx gamosepalous usually of 5 sepals, inferior or superior. Corolla 

 regular polypetalous usually of 5 petals. Stamens many perigynous. Pistil 

 apocarpous (spuriously syncarpous when the calyx tube is adherent to the 

 ovary). Fruit a pome or of one or many drupes or achenes or follicles. 

 Ripe carpels not enclosed within the calyx tube, 237 

 Ripe carpels enclosed within the calyx tube, 238 



237 Herbs, 239 



237 Shrubs, 240 

 238 Herbs, 241 

 238 Shrubs, 242 



239 Sepals equal, 243 



239 Sepals with alternate smaller segments, 244 



240 Style I, , Prunus I. 



240 Styles many, Rubus II. 



241 Petals 5, Agrimonia IH. 



241 Petals o, 246 

 242 Carpels i — 5, 247 

 242 Carpels many, . . Rosa IV. 



243 Leaves simple, ....... Dryas V. 



243 Leaves pinnate, ....... Spiraea VI. 



244 Achenes with a long jointed awn, ..... Geum VII. 



244 Achenes with a short style, 245 



245 Achenes on a fleshy receptacle, . . . Fragaria VIII. 



245 Achenes on a dry receptacle, .. . . Potentilla IX. 

 246 Stamens i — 4, 248. 

 246 Stamens many, Poterium X. 



247 F^ruit a fleshy pome (endocarp cartilaginous), . Pyrus XIV. 



247 Fruit a drupe enclosing one or more bony 



stones (endocarp bony). .... Crataegus XIII. 



248 Calyx 4 -cleft, Sanguisorba XI. 



248 Calyx 8-cleft, Alchemilla XII. 



I.— PRUNUS, 

 Calyx deciduous 5-cleft, petals 5, ovary solitary superior, fruit a drupe. 



PRU'NUS COMMU'NIS (103). Sloe, Blackthorn. 4—5. Flowers 

 (407, 408) one or two together, leaves elliptical, branches spinous. Copses. 



