ROSACEAE. 



Pistil one. 



Fruit a drupe; petals present. 

 Fruit an akene; petals none. 



Shrubs or small trees; leaves not lobed. 

 Herbs; leaves lobed. 



Leaves palmately lobed; flowers axillary. 

 Leaves pinnately lobed ; flowers in a spike. 

 Pistils more than one. 



Pistils 2-5, united with each other and with the 

 lower part of the receptacle and calyx-tube 

 with which in fruit they form a pome. 

 Flowers in racemes; locules of mature pomes 



10. 



Flowers in corymbs or cymes; locules 1-5. 

 Carpels stony in fruit; plant thorny. 

 Carpels papery in fruit; plant not thorny. 

 Pistils few or many, free. 



Fruit of few 2-several-seeded follicles. 

 Leaves palmately lobed. 

 Leaves not palmately lobed. 



Stamineal disk adherent, entire; ovules 



2. 

 Stamineal disk free at the edge, not 



entire; ovules 5 or more. 

 Fruit of numerous 1-2-seeded akenes or drupe- 

 lets. 



Fruit of drupelets, usually united. 

 Fruit of akenes. 



Receptacle urn-shaped or bell-shaped, 



enclosing the akenes. 

 Receptacle fleshy; akenes numer- 

 ous; petals present. 

 Receptacle dry; akenes 1-4; petals 



none. 

 Leaves palmately lobed ; flowers 



axillary. 

 Leaves pinnately lobed ; flowers 



in a spike. 



Receptacle flat or but slightly concave. 

 Styles persistent, mostly plumose or 



geniculate. 

 Styles jointed, the upper part 



deciduous. 

 Styles not jointed, plumose or 



naked. 



Styles deciduous, naked. 

 Styles terminal. 



Stamens near the base of the 

 receptacle-cup on a thick- 

 ened ring. 



Stamens well up on the re- 

 ceptacle-cup; no thick- 

 ened ring. 

 Styles lateral. 



Stamens 5; carpels 10-15. 

 Stamens 20; carpels numer- 

 ous. 



Leaves trifoliolate ; re- 

 ceptacle fleshy in fruit. 



184. PRUNUS, 132. 



185. CERCOCARPUS, 132. 



194. ALCHEMILLA, 137. 



195. SANGUISORBA, 138. 



186. AMELANCHIER, 133. 



187. CRATAEGUS, 133. 



188. PYRUS, 134. 



189. OPULASTER, 134. 



190. HOLODISCUS, 135. 



191. SPIRAEA, 135. 



192. RUBUS, 136. 



193. ROSA, 137. 



194. ALCHEMILLA, 137. 



195. SANGUISORBA, 138. 



196. GEUM, 138. 



197. SIEVERSIA, 139. 



198. POTENTILLA, 139. 



199. IVESIA, 140. 



200. SlBBALDIA, 140. 



201. FRAGARIA, 141. 



