GERMINATION OP TREES AND SHRUBS 



331 



cent. Cotyledons yellowish, at first soon becoming green, elon- 

 gated, narrowly elliptical, smooth, fleshy; hypocotyl reddish, 

 smooth, straight, tapering. The plumule appears as a little 

 protuberance between the cotyledons ; stem between the root and 

 cotyledons reddish. In about ten days the plumule pushes out 

 and is folded, slightly pubescent on midrib, more pubescent on 

 the margin, conspicuously veined. Root soon produced, bear- 

 ing lateral rootlets. First leaves two, opposite, acute, widely 

 dentate or entire, some pubescence on the margin ; third, fourth 

 and fifth leaves simple. 



Pig. 106. — Germination of Ohio bucl<;eye (Aesoulus glabra), lower leaves 

 small, gradually becoming larger, then conapound, of five leaflets. Photo- 

 graphed by Photo. Section, F. E. Colburn. 



SAPINDACE.^. 



Aescuhis glabra Willd. Buckeye. Seeds gathered at Center- 

 ville, Iowa, on September 29, 1917 ; stratified in humus in cold 

 frame covered with manure, on October 10, 1917. The seeds 

 were removed to the greenhouse on March 14, 1918, just as the 

 frost was leaving the ground. The first germination appeared 

 March 23. Total germination 100 per cent. Germination hypog- 

 feous. Stem reddish, at first pubescent, becoming smooth. First 

 two leaves (plumule) alternate, simple, reddish, slightly pubes- 

 cent on the upper surface, smooth below, marf.in distantly den- 



