GERMINATION OF TREES AND SHRUBS 



315 



the radicle. Leaves of plumule arlaiidiilar pubescent, serrate. 

 The first pair of leaves small, apparently opposite, third and 

 fourth jDair similar, slightly hair\^ on lower surface, more hairs 

 on the teeth, stem pubescent, hairs not glandular. Roots ap- 

 proximately alternate. Seeds placed in moist chamber June 30, 

 90 per cent germinated in five or six days. Seeds placed on 

 moist surface of soil and exposed to laboratory atmosphere ger- 

 minated 18 per cent. Seeds dried two weeks in laboratory ger- 

 minated per cent. 



Fis. 75 



Fig. 76 



Fig-. 75. — UUnus americuna, seedling ; a, natural size. Drawn by C. M. 

 King. 



Fig. 76. — Trichomes from leaf of seedling Uluins fnlva, showing two glan- 

 dular hairs from the same leaf. Drawn by C. M. King. 



Tlnius fiilva Michx. Sli]:)pery or Red Elm. Bloom May 1, 

 IDIT. seeds falling May 26, 1917, seeds collected from field and 

 kept in moist eham'ber, germinating in 14 days. Collected on 

 campus, I. S. C, May 18, 1918, germinating freely in the field 

 on date of collection, radicle appearing first, germination epig- 

 a?ous, hypoeotyl red, pubescent, a straight tap root, cotyledons 

 aurieulate, petiole pubescent, leaves oval, with scattered hairs 

 on upper surface ; pubescent on veins and margins of both upper 

 and lower surface. Serrations of leaf glandular tipped, glands 

 reddish, thin- walled, distinctly stalked ; chlorophyll-bearing tis- 

 sue entering up into the gland. Trichomes one-celled, thin- 



