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IOWA ACADEMY OF SCIENCE Vol. XXY. IDIS 



closely pubescent. At height of three inches the petioled leaf 

 develops, with, three leaflets, pinnate, ovate, serrate. The plant 

 p-enerally pubescent. At this stage of development the radicle is 

 about twelve inches long, and one-third inch in diameter. Seeds 

 planted in out door seed-bed, germinatetl by June 5, about 5 per 

 cent. 



Fig. 59 Fig. 58 



Fig. .57. — Germination of pig nut (Curya cordiformis), scales lielow tlie 

 first compound leaf. Photographed by Photo. Section, F. E. Colburn. 



Fig. 58. — Germination of common hazel nut (Corylus americuna') , phow- 

 ing nut caulicle and two branches. Photographed by Photo. Section, F. E. 

 Colburn. 



Fig. 59. — Young seedling of gray or cherry birch (Betitlu lutca), small 

 cotyledons, alternate coarsely toothed leaves. Photographed by Photo. Sec- 

 tion, F. E. Colburn. 



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