Spanish Clover, Lotus purshianus

Growing along the railroad tracks near the train station on Yacolt Creek in SW Washington, this member of the Pea family has very small flowers that are easy to miss.

Saddle Mushroom, Helvella elastica

 I found this odd looking mushroom near Moulton Falls on the East Fork of the Lewis River in SW Washington.  Many thanks to lycopus on gardenweb.com, name-that-plant forum for the ID.

Stinging nettle, Urtica dioica

This is one annoying plant!  No friend to hikers, stinging hairs contain formic acid that irritate the skin when touched even lightly.

 Flower closeup:

Stinging hairs: