ROSACEAE 123 



Carpel only one. 



Fruit an achene or drupe. 1. Rosaceae. 



Fruit a legume. 



Flowers in heads, petals valvate. 2b. Mimosaceae. 



Flowers not in heads, petals imbricated. 2a. Caesalpinaceae. 

 Ovary inferior, carpels united. 



Fruit a many seeded berry, shrubs, usually spiny. 



4. Saxifragaceae. 

 Fruit a pome, trees or shrubs. 1. Rosaceae. 



Flowers irregular. 

 Stamens distinct. 



Trees. 2a. Caesalpinacesc. 



Herbs. 2c. Papillionaceae. 



Stamens united by their filaments. 2c. Papillionaceae. 



Flowers in dense globular heads, monoecious. 5. Platanaceae. 



1. ROSACEAE. 



Pistils 1-2 ovuled, generally 1 seeded in fruit, indehiscent. 



Pistils distinct from each other and from the receptacular cup. 

 Pistils and achenes numerous. 



Pistils and achenes not enclosed by the receptacle. 



Calyx with a whorl of 5 bracts making it appear double. 

 Styles terminal, flowers mostly yellow. 



Styles small, not elongating in fruit, neither plumose nor 



jointed . 1. Potentilla. 



Styles elongating in fruit, plumose and often jointed. 



4. Geum, 

 Styles lateral, flowers white. 



Plants acaulescent, receptacle fleshy, edible. 3. Fragaria. 



Plants caulescent, receptacle dry. 2. Drymocallis. 



Calyx without bracts, pistils developing into a berry-like 



aggregate. 5. RuDus. 



Pistils and achenes enclosed by the receptacular cup. 9. Rosa. 



Pistils and achenes 1-4. 



Herbs, achenes enclosed in the dry urn-shaped receptacle. 

 Petals none, sepals petaloid, without prickles; flowers in dense 

 heads or spikes. 7. Sanguisoroa. 



Petals yellow, calyx prickly, flowers in racemes. 



8. Agrimonia. 

 Trees or shrubs, pistil solitary. 



Petals none, style persistent, long and plumose, fruit an 



achene. 6. Cercocarpus. 



Petals present, fruit a drupe. 14. Prunus. 



Pistils united to each other and to the receptacular cup, fruit a pome. 



Inner wall of the ripe carpels bony, ovule one in each carpel, or 



if 2, dissimilar. 12, Crataegus. 



Inner wall of the ripe carpels papery. 



Pome 5-6 cm. in diameter, cells 2 seeded, as many as the styles. 



11. Malus. 



Pome less than 1 cm. in diameter, cells 1 seeded, twice as many 



as the styles. 13. Ameianchier. 



Pistils with several ovules, 2-4 seeded dehiscent. 10. Opulaster. 



