Sweet Marsh Groundsel, Stout Meadow Groundsel, Tall Groundsel: Senecio hydrophiloides (Synonyms: Senecio foetidus, Senecio foetidus var. foetidus, Senecio foetidus var. hydrophiloides, Senecio oreganus) - Large, native perennials. Plants can appear to be either entirely discoid or can have flowerheads with both disc and ray flowers.
Alkalik Marsh Butterweed, Alkali Marsh Ragwort, Water Groundsel, Water Ragwort: Senecio hydrophilus (Synonym: Senecio hydrophilus var. pacifica) - Large, native perennials. Plants can appear to be either entirely discoid or can have flowerheads with both disc and ray flowers.
Common Groundsel, Old-main-in-the-Spring: Senecio vulgaris - Small annual weed.