190 
GOTE TURESSON 
Stages of the river, e. g., in the ravine. Wherever the topography 
in the gully admits water to remain during the earlier part of the 
vegetative season the conditions are favorable for the establishing 
of Lysichiton. Water-pockets of about three meters' circumference 
and located in the bottom of a ravine at Maltby, north of Lake Wash- 
ington, State of Washington, showed the following vegetation (April 
1915): Lysichiton camtschatcense,^ Cardamine pennsylvanica, Ranun- 
culus bongardi greenei. The pools were partly filled with humous 
material slid down from the slopes together with leaves of the trees 
in the immediate vicinity, Acer macrophyllum, Alnus oregona and 
Rhamnus purshiana. 
Fig. I. Lysichiton camtschatcense at the time of flowering. Author's photo- 
graph. 
With the appearance of a permanent stream in the ravine the 
conditions become still more favorable for Lysichiton. It is true, 
the erosive action of the stream at first prevents vegetation from 
^ In questions of nomenclature Piper's Flora of the State of Washington (19) 
has been followed 
