Alkali-Marsh Butterweed
Senecio hydrophilus  Nutt. 

A waxy bog bi-annual/perannual with smooth-edged, lance-shaped leaves that are reduced upwards.  It grows 2-6 feet tall. There are yellow-ray or disk flowers that form heads that are 1/4 to 1/2 inch across.  It flowers from May to the first part of July.  A perennial herb that is confined to western North America. Found in medium dry to moist soil in open areas, gullies, prairies, and in mountains up to the timberline.  Found throughout the western U. S. An original specimen at the British Museum from the Nuttall collection bears the datum Lewis' River.