United States, California, MARIPOSA, LOWER RIVER CAMPGROUND, YOSEMITE VALLEY, YOSEMITE NATIONAL PARK, CALIFORNIA; 2M EAST OF SOUTHERN END OF MARSHY AREA IN NORTHERN HALF OF CAMPGROUND; LEVEL; WET, SANDY SOIL WITH LIGHT LITTER; NO CANOPY COVER; ASSOCIATED SPECIES: COLLOMIA GRANDIFLORA, PINUS PONDEROSA SEEDLINGS; AREA FLOODED IN 1997.