242 ERYTHEA. 
of the explorer passes on through the labyrinth of 
channels, ascending sloughs and rounding bends, and the 
shining reaches of water are ever bounded by the thin 
wall of foliage. One may force his way through the thicket 
of brambles and underbrush beneath these river trees, and 
then there is another expanse—not of water, but of the 
masses of waving tule [Scirpus lacustris, var. occidentalis, 
Wats. | which chokes the marsh lands. 
The trees and shrubs are of those species characteristic of 
such situations. The major part of the growth is made up 
of various species of willow [Salix nigra, Marsh, S. lasian- 
dra, Benth., and S. longifolia, Muhl.]. Fine specimens of 
the Plane Tree [ Platanus racemosa, Nutt.] are not uncom- 
mon. The Cottonwood [Populus Fremonti, Wats.] is fre- 
quent; while the Button Bush [Cephalanthus occidentalis, 
L.], the Oregon Ash [ Fraxinus Oregana, Nutt.], the Cali- 
fornia Walnut [Juglans Californica, Wats.], and the 
Alder [Alnus rhombifolia, Nutt. ], though not abundant, are 
to be met with throughout this entire region. The Wild 
Grape [Vitis Californica, Benth.] was noticed in several 
places. The undergrowth is largely a tangle of California 
Wild Rose [Rosa Californica, O. & 8.] and Blackberry 
[Rubus vitifolius, 0. & §.], with various herbaceous and suf- 
frutescent plants. The Box-Elder [Acer Californicum, 
Greene] and Poison Ivy [Rhus diversiloba, T. & G.] were 
noticed near Walnut Grove, as also fine individuals of the 
Live Oak [Quercus Wislizeni, DC.] on the highest river 
banks. The River Dogwood [Cornus pubescens, Nutt.] is 
fairly frequent. The leaves of the sterile shoots are very 
different from the normal form, being round-ovate and 
abruptly short acuminate. 
In the cultivated areas the native vegetation has mostly 
been driven out and instead appears a wilderness of foreign 
weeds hardly remarkable in any respect save in their size. 
Erigeron Canadensis grows from five to eight feet high, a5 
does Ginothera biennis. Portulaca oleracea, which in moist 
situations in the Coast Range spreads over the ground cover- 
