Proceedings of the Ohio State Academy of Science 109 



17. Stamens of the same number as the petals and opposite 



them; ovulary 2-5-locular, calyx 4-5-cleft, valvate in the 

 bud ; petals involute ; fruit a drupe or capsule ; shrubs, 

 small trees, or vines with simple leaves. Rhamnaceae. 



a. Rhamnus. (60). 



18. Carpels i or more, united, but styles and stigmas may be 



several. 19. 

 18. Carpels more than i, distinct; filaments shorter than the 

 anthers ; perianth trimerous ; leaves 2-ranked. Anon- 



ACEAE. 



a. Asimina. (34). 



18. Carpels numerous spirally arranged and cohering over each 



other, forming an aggregate cone-like fruit ; trees ; sepals 

 and petals in threes ; twigs with stipular rings. Magnol- 



lACEAE. 



a. Anthers introrse ; leaves not truncate. Magnolia (32). 

 a. Anthers extrorse ; le;aves truncate. Liriodendron. (33). 



19. Ovulary compound, plurilocular. 20. 



19. Ovulary i-locular, 2-ovuled ; fruit a drupe with i seed. 



ROSACEAE. (DrUPATAE). 



a. Drupe glabrous, stone smooth or nearly so. 



Prunus. (42). 

 a. Drupe velvety, stone deeply pitted. Amygdalus (43). 



20. Calyx deciduous ; flower cluster subtended by a large mem- 



branous bract ; trees with alternate, 2-ranked leaves and 

 mucilaginous sap. Tiliaceae. 



a. Tilia. (16). 



20. Leaves alternate with deciduous stipules ; ovulary composed 

 of 2-5 wholly or partly united carpels ; fruit a more or 

 less fleshy pome. Rosaceae. (Pomatae). 

 a. Ripe carpels papery or leathery, b. 



a. Ripe carpels bony. Crataegus. (41). 



b. Leaves pinnate. Sorbus. (36). 



b. Leaves simple, c. 



c. Cavities of the ovulary as many as the styles, d. 



