I went hiking around the Olympic peninsula in Washington State back in late July and snapped a few pictures of submersed and emersed plants along the way. Some were taken with my iPhone, so the quality isn't the greatest.
From Lake Crescent:
Signs mentioned a rare plant in the lake called, Lobelia dortmanna, but I never saw it.
The most interesting areas plant-wise were streams near the Hoh river.
This plant looks like mini pellia:
Near the Hall of Mosses was this beautiful cluster of plants. Hopefully they were all natives!
The moss had an interesting silvery color when the light hit it right that I couldn't tell was due to the moss itself or an algae growing on it.
I can't recall where I saw this one.
A Fissidens? near Lake Quinault
It was an amazing area to hike. Late July was perfect: I saw very little rain. Maybe our local experts can identify some of these plants.
Doug