108 Proceedings of the Ohio State Academy of Science 



a. Staminate flowers racemose or spicate, the carpellate 

 capitate, b. 



a. Staminate and carpellate flowers in ament-like spikes. 



Morus. (26). 



b. Carpellate perianth deeply 4-cleft ; twigs with thorns. 



Toxylon. (27). 

 b. Carpellate perianth 3-4 toothed ; twigs not thorny. 

 Broussonetia. (28). 

 15. Trees with alternate, palmately lobed, fragrant leaves; the 

 flowers in dense heads, the carpellate ones long-peduncled. 

 Hamamelidaceae. 



a. Liquidambar. (30). 



15. Shrubs or trees with 9 or 12 stamens in 3 or 4 cycles; 

 anthers opening by valves; aromatic; fruit a i -seeded 

 drupe or berry. Lauraceae. 



a. Sassafras. (35). 



15. Shrubs or trees with simple leaves, with 4-5 perigynous sta- 

 mens alternate with the sepals ; ovulary 2-5-locular, ovules 

 solitary in each cavity, stigmas 2-5 ; fruit a drupe. 

 Rhamnaceae. 



a. Rhamnus. (60). 



15. Trees with simple alternate leaves and diaphragmed but 



solid pith; stamens 5-15, flowers epigynous; ovulary uni- 

 locular with I pendulous ovule. Some Cornaceae. 



a. Nyssa. (76). 



—16— 



16. Flowers hypogynous or perigynous; ovulary free from the 



calyx or adherent to the perigynous disc. 17. 



16. Flowers epigynous ; calyx above the ovulary. 33. 



17. Stamens numerous, at least more than 10 and more than 



twice the petals. 18. 

 I/'. Stamens not more than twice as many as the petals, when of 

 just the number as the petals then alternate with them. 

 21. 



