The Oxalis Family in the Cascade Mountains of Oregon and Washington

Creeping Yellow Wood-sorrel, Creeping Wood-sorrel: Oxalis corniculata (Synonym: Oxalis violacea) -

Graygreen Sorrel, Slender Yellow Wood-sorrel, Southern Yellow Wood Sorrel: Oxalis dillenii (Synonym: Oxalis corniculata var. dillenii) -

Oregon Wood Sorrel, Redwood Sorrel, Sour Grass, Western Wood Sorrel: Oxalis oregana (Synonyms: Oxalis oregana var. oregana, Oxalis oregana var. smallii) - Herbaceous ground cover. The flowers with 5 petals are generally white or white with red candy stripes. the leaves are a key diagnostic characteristic, being 3 heart-shaped leaflets with the apex of each leaflet pointed in towards the stem.

Common Yellow Oxalis, Upright Yellow Wood-sorrel, Yellow Wood-sorrel: Oxalis stricta (Synonyms: Oxalis ambigua, Oxalis bushii, Oxalis coloradensis, Oxalis cymosa, Oxalis europaea, Oxalis fontana, Oxalis interior, Oxalis rufa) -

Western Yellow Wood-sorrel, Western Yellow Oxalis, Suksdorf's Wood-sorrel, Suksdorf's Oxalis: Oxalis suksdorfii (Synonyms: Oxalis corniculata var. macrantha, Oxalis pumila, Xanthoxalis suksdorfii) -

Great Wood-sorrel, Great Oxalis, Trillium-leaf Wood-sorrel, Trillium-leaved Oxalis: Oxalis trilliifolia (Synonym: Hesperoxalis trilliifolia) -