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IOWA ACADEMY OF SCIENCE Vol. XXV, j918 



Availed, sliuhtly eiilarued at base; either straight or sliu'htly 

 curved, of variable length. Gerininatiou in laboratoi'v 10 per eeut. 

 The slippery elm, from our experience, does not ii'erminate in the 

 laboratory as freely as the Chinese elm and the American elm. 

 Seeds p-erniinatinK fi-eelv ont of doors, Mav 25. 



Fig-. 77. — 1. Seedling of Uhuus fnJva; 2, 3, leaves of same; 4, margin of 

 leaf: 5. trichome more enlarged; G, glandular hairs; 7. cotyledon. Drawn by 

 C. M. King. 



rhuiis pumila L. Ckinese Elm. Seeds of this elm were col- 

 l(>cted on the campus ]\Iay 18, 1918. On May 20, the seeds showed 

 a germination of 98 per cent. A young seedling- colleoted from 

 the field at the same time was used for description. Germina- 

 tion epigffious, seeds g'erminate from the apical seed, caulicle 

 light colored, glandular pubescent. Tap root straight, with nu- 

 merous root-hairs and prominent root cap. Cotyledons fleshy, 

 upper .surface glandular p.ubescent; slightly aurieled, truncate, 

 soon falling, smooth above and below. Stein puliescent. First 



