GERMINATION OF TREES AND SHRUBS 



327 



the soft maple which germinates soon after the seeds are ripe. 

 The cotyledons are green in color. 



Both Acer saccharimim and Acer rubrum germinate freely in 

 the field. Sargent-^ states that the seeds of the two American 

 species with precocious flowers, Acer saccharum and Acer rii- 

 hrum, ripen at the end of a few weeks after the trees flower and 

 srerminate at once. 



Fig. 99 ■ Fig. 100 



Fig. 99. — ^Germination of Acer saccharimim. 1, radicle appearing first : 

 2, radicle and hypocotyl developing at same time ; 3, cotyledons, radicle and 

 plumule displayed. Drawn by C. M. King. 



Fig. 100. — Seedling of Acer saccharinum. Drawn by C. M. King. 



ACERACE^. 



Acer. The seeds of the maples germinate in two days. Epig- 

 aeoiis germination is represented by the common black maple 

 (Acer nigrum) the sugar maple (Acer saccharum) the red maple 

 [Acer ruhrimi) and the box elder (Acer negundo). The common 

 soft maple (Acer saccharinum) is the only i-ative tree species 



=».The silva of North America, 2, pp. 79, 104. 



