Early Blue Violet, Hookedspur Violet, Long-spurred Violet, Western Longspur Violet: Viola adunca (Synonyms: Viola adunca ssp. ashtonae, Viola adunca ssp. oxyceras, Viola adunca ssp. radicosa, Viola adunca ssp. typica, Viola adunca ssp. uncinulata, Viola adunca var. adunca, Viola adunca var. bellidifolia, Viola adunca var. cascadensis, Viola adunca var. oxyceras, Viola adunca var. uncinulata, Viola aduncoides, Viola bellidifolia, Viola cascadensis, Viola montanensis, Viola oxyceras, Viola subvestita) - Flowers purple or violet, often with white throat with purple pencilling. Spur behind petals is slender & 1/2 the length of the lowest petal. Leaves lance-shaped.
Baker's Violet, Yellow Prairie Violet: Viola bakeri (Synonyms: Viola bakeri ssp. grandis, Viola bakeri ssp. shastensis, Viola nuttallii, Viola nuttallii var. bakeri) - Leaves simple; basal 1–4 per caudex, petiole 1–14 cm, blade 1.8–8.8 cm, 0.7–3.9 cm wide, lanceolate, oblanceolate, elliptic (ovate), thin, margins usually entire, base obliquely tapered, tip obtuse or acute; cauline petiole 1.5–7.5 cm, blade 1.9–6.7 cm, 0.5–1.6 cm wide, ± like basal. Petals deep lemon-yellow, upper 2 often maroon or ± brown on the backside, lower 3 veined brown-purple.
Pioneer Violet, StreamViolet, Wood Violet: Viola glabella - Yellow flowers with 5 petals of different shapes. The lower petal has lines on it. Leaves are heart-shaped. Herbaceous wildflower to 6 inches tall.
Howell's Violet: Viola howellii - Petals white with purple or blue shading on the back. Spur behind petals broad and pouched less than half as long as the lowest petal.Leaves kidney-shaped or oval, not more than 2 times longer than wide.
Northern Bog Violet: Viola nephrophylla (Synonyms: Viola nephrophylla var. cognata, Viola nephrophylla var. nephropylla, Viola sororia, Viola sororia ssp. affinis, Viola sororia var. affinis) -
Sweet Blue Violet, Sweet Violet: Viola odorata - Introduced species.
Darkwoods Violet, Evergreen Yellow Violet, Round-leaf Violet, Round-leaved Violet: Viola orbiculata (Synonyms: Viola sempervirens var. orbiculata, Viola sempervirens var. orbiculoides) - Flowers yellow. Leaves thin, heart shaped, but about as broad as long with rounded tips. No purple flecks appear on the leaf surface. The leaves do not persist through the winter.
Marsh Violet: Viola palustris (Synonyms: Viola palustris var. brevipes, Viola palustris var. palustris) - Flowers white to lavendar with green to lilac-tinged purple lines on the lower 3 petals. Leaves oval or kidney-shaped to broadly heart-shaped, 2.5-3.5 cm wide. Flowers and leaves arise independently from the rhizome. Common in moist meadows and along streams.
Upland Yellow Violet, Wavyleaf Violet: Viola praemorsa ssp. linguifolia (Syonyms: Viola flavovirens, Viola linguifolia, Viola nuttallii var. linguifolia, Viola nuttallii var. major, Viola praemorsa ssp. arida, Viola praemorsa ssp. flavovirens, Viola praemorsa ssp. major, Viola praemorsa ssp. oregona, Viola praemorsa, var. altior, Viola praemorsa var. linguifolia, Viola vallicola var. major) - basal and cauline, blade generally elliptic, base generally tapered, often oblique; basal 5–8.5 cm, much longer than wide, ± entire, ± crenate, serrate, wavy, or generally irregularly toothed; cauline 1.4–3.5 cm wide.
Canary Violet, Upland Yellow Violet: Viola praemorsa ssp. praemorsa (Synonyms: Viola nuttallii ssp. praemorsa, Viola nuttallii var. praemorsa) - Yellow flowers with 5 petals of different shapes. The lower petal has dark lines on it. The leaves are several inches long, oblanceolate (about 2-4 times longer than wide.). The upland yellow violet is an herbaceous wildflower to eight inches tall. basal and cauline, blade generally ovate, base generally ± truncate; basal 2.3–6.7 cm, not much longer than wide, ± crenate or serrate, wavy, or entire; cauline blade 1.3–3 cm wide.
Evergreen Violet, Redwood Violet, Redwoods Violet: Viola sempervirens (Synonym: Viola sarmentosa) - Flowers yellow. Leaves firm and leathery, shiny surfaced, finely dotted with purple mottling, and persistent through the winter. Leaves about as wide as long, heart-shaped with more pointed blade than Viola orbiculata.
Cut-leaf Violet, Fan Violet, Shelton's Violet: Viola sheltonii (Synonym: Viola biternata) - Yellow flowers with 5 petals of different shapes. The lower petal has dark lines on it. The leaves are deeply cut, to be essentially compound-palmate.
Northern Bog Violet: Viola sororia ssp. affinis (Synonyms: Viola affinis, Viola chalcosperma, Viola nephrophylla, Viola nephrophylla var. cognata, Viola nephrophylla var. nephrophylla, Viola rosacea, Viola sororia var. affinis) -
Desert Pansy, Rainier Violet, Sagebrush Violet, Three-nerved Violet: Viola trinervata - Flowers bicolored, the upper pair deep reddish-violet, the lower 3 pale to medium lilac with yellow or whitish base & purple pencilling. Leaves compound, the segments leathery, prominently 3-nerved, smooth-surfaced, and elliptic in shape. Once seen in the eastern Gorge, this species is now generally found several miles north or south of the Columbia River Gorge in the Klickitat and Deschutes River drainages.
Sagebrush Violet, Valley Violet, Valley Yellow Violet, Yellow Sagebrush Violet: Viola vallicola var. major (Synonyms: Viola nuttallii, Viola nuttallii ssp. vallicola, Viola nuttallii var. major, Viola nuttallii var. vallicola, Viola russellii, Viola vallicola var. vallicola) -