430 IOWA ACADEMY OF SCIENCE Vol. XXV, 1918 



Stunted shnit). Some fair sized trees occur. The wood is heavj' 

 and resinous. 



Abies amahilis (Loud.) Forbes. What appears to be this fir 

 occurs along Taku river. 



Picea sitchensis (Bong.) T. & M. Sitka or Tideland Spruce. 

 This is the dominant forest tree of southeastern Alaska. At- 

 tains large size and is the chief source of lumber and firewood. 

 The lumber has recently come into great demand for aeroplane 

 building. 



Tsuga heterophylla (Raf.) Sarg. Western Hemlock. Next 

 to Sitka spruce this is our largest and most abundant forest 

 tree. Attains a diameter of four feet. 



Tsuga mertensiana (Bong.) Carr. Black or JMountain Hem- 

 lock. A small tree, infrequent near sea level 'but increasing in 

 abundance as one ascends. It is essentially a timber line tree, 

 on alpine summits often forming masses of spreading bashes a 

 few feet high but with trunks sometimes eight to ten inches in 

 diameter. 



SPARGANIACE^. 



SpaJiganium angustifolmm ]\fichx. Collected in Swan lake, 

 Sitka. 



Sparganium minimum Fries. Collected in some small pools 

 at Mendenhall. 



NAIDACE^. 



Potam&fjeton heterophyllus Schreb. Both this and the fol- 

 lowing species are frequent in lakes and ponds, around Sitka. 



Potamogeton natans L. 



Zostera. marina L. Eel Grass. Yerj^ common off the shore, 

 rooting just below low tide. 



SCHEUCHZERIACE^. 



Triglochin maritima L. Common along the seashore, especially 

 the parts of tide flat-s covered only at the very liigh tides. 



POACE^. 



Echinocloa crus-galli (L.) Beauv. Barnyard Grass. Has 

 been introduced with feed but does not seem able to maintain 

 itself. 



Phleum pratense L. Timothy. This grass has been intro- 

 duced around towns, canneries, etc., where it finds no difficulty 

 in maintaining itself. 



Phleum, alpimim L. Mountain Timothy. Fairly common in 

 wet soil along streams and on open mountain sides. 



