ALDER 



259 



ovate to lanceolate, fringed with glandular hairs. Young 

 leaves viscid above. Autumn leaves deep brown to black. 

 Venation strict-pinnate, the midrib straight, strong 

 below, tapering to a capillary end ; secondaries 5 7 pairs, 

 straight or the lower slightly diverging to the margin and 



-a 



Fig. 93. Alder, Alnus glutinosa. Venation strict-pinnate, a midrib ; 

 b secondary; c tertiary; d quaternaries and terminals forming network, 

 p. 258 (Ett). 



ending in teeth, or mostly forking at the apex, or giving 

 off strong outer nerves, which do so : angle 50 65 degrees. 

 Tertiaries at acute angles, sinuous, not looped beneath the 

 bi-serrate margin, and often forming complete cross-ties 

 before anastomosing. Each pair of secondaries distant 



172 



