Ramaley : SEEDLINGS OF CERTAIN WOODY PLANTS. 77 



broad, but grow rapidly and become about twice that size. As 

 they grow older they become broader in proportion to the length. 

 The petiole is finally about 5 mm. long. The hypocotyl tapers 

 gradually to the root so that its exact limit is not easily recog- 

 nized. It reaches a length of 40 or 50 mm. 



The epicotyl is about 15 mm. long. Leaves are all alternate. 

 The first leaves are not different from those formed later. 



ACERACE^E. 

 Acer negundo LINN. 



Seeds of the "box-elder" germinate in from one to two 

 weeks after sowing. The large winged pericarp is brought 

 above ground. 



The hypocotyl is 25-35 mm. long when the cotyledons first 

 open and does not grow longer. The cotyledons are strap- 

 shaped, sessile, entire, tri-veined ; about 30 mm. long and 5 mm. 

 broad. 



The epicotyl becomes 5-8 mm. long. Leaves are opposite. 

 The first two are ovate, acute, serrate, petiolate. Later ones 

 are tri-cleft. Usually the sixth or seventh pair and all later 

 ones are pinnately compound. 



Acer glabrum TORR. 



The seedling of the " Rocky mountain maple " resembles that 

 of A. negundo. The hypocotyl is shorter, 20 mm. long, and 

 the cotyledons about 20 mm. long, 5 mm. broad. Leaves are 

 opposite, long-petioled, ovate-cordate, the second pair somewhat 

 lobed. Later leaves are three- or five-lobed, the lobes more or 

 less acute and sharply serrate. 



Acer saccharinum LINN. 



The seeds of the " soft maple" germinate in about ten days 

 after planting. The first leaves are well developed when the 

 plant appears above ground. The cotyledons remain in the 

 soil for a time enclosed in the pericarp which eventually decays. 

 Sometimes they do not appear above ground * at all. 



The hypocotyl is stout, about 20 mm. long. The cotyledons 

 are somewhat fleshy, asymmetrical, short-petioled, bent around 



*Winkler. Kleinere morph. Mittheilungen, in Verhandl. d. Bot. Ver. d. 

 Provinz Brandenburg, 18 : 99. 1877. 



