350 University of California Publications in Zoology. |Vouo 
chiefly to the immediate vicinity of the coast, attaining timber- 
line in only a few localities. About the rocky shores of the 
fiords it grows to the very edge of the water, its graceful branches 
often sweeping the surface at high tide. Much of the beauty 
and charm of this tree is due to its smaller proportions at this 
latitude. (No. 15.) 
Tsuga mertensiana (Bonge.) Carr. Mountain Hemlock. 
Almost as numerous individually as the spruce. A mountain 
species primarily, it here reaches the coast and becomes of uni- 
versal distribution on the hillsides from timber-line to sea-level. 
At the upper limit of coniferous forests it becomes a prostrate, 
shrub-like growth, often covering extensive areas. About the 
swampy margins of tundras it flourishes unhampered by other 
forest growth, apparently being better suited to such wet con- 
ditions than any other conifer of the region. The wetter por- 
tions of these swamps, however, are not adapted for this hardy 
species and the few trees that have attempted an invasion stand 
dwarfed near their margins. (Nos. 22, 46.) 
Picea sitchensis (Bong.) Traut. & Mayer. Sitka Spruce. 
The most abundant, wide-spread and largest tree of the 
region. Occurs practically everywhere where forests occur, from 
sea-level to timber-line. At the upper limit of forest growth 
it becomes a prostrate shrub and vies successfully with the 
mountain hemlock. Forests of pure growth occur throughout 
the floors of the larger valleys and stream deltas, but elsewhere 
it occurs mixed with the two hemlocks of the region. (No. 14.) 
Elymus mollis Trin. Rye-grass. 
Confined to the marine littoral. On all the heavy gravel 
beaches and spits of recent origin this grass forms a dense 
erowth. As these gravel formations are of small extent and 
widely isolated, this grass is correspondingly of limited distri- 
bution. (No. 3.) 
Carex, sp. Saw-g2rass. 
The deltas of ereeks and their margins were covered by a 
heavy growth of this sedge wherever there were fresh-water in- 
fluences. Most of the territory occupied by this species was 
flooded daily by back water during high tide. (No. 12.) 
