ALDERS. 
27 
I . The seed-vessel furnished with a membranaceous winged 
margin , and with the scales of the fertile ament retuse or 
obscurely lobed. 
The White Alder, ( Mnus incana.) 
The Oregon Alder, ( Alnus Oregona .) 
The Heart-leaved Alder, ( Mnus cordata.) 
Mountain Alder, ( Mnus viridis.) 
II. The margin of the seed-vessel thick and opaque , and 
with the scales of the fruiting ament distinctly lobed . 
Common Alder, ( Mnus glutinosa . ) 
Fine-toothed Alder, ( Mnus serrulata.) 
Sea-side Alder, ( Mnus maritima.) 
Oblong-leaved Alder, ( Alnus oblongata.) 
Short-leaved Alder, ( Alnus brevifolia.) 
Rhombic-leaved Alder, {Mnus rhombifolia.) 
