The Genus Hydrophyllum
Ball-head Waterleaf: Hydrophyllum capitatum var. thompsonii
Ball-head Waterleaf, Grandma's Pincushion, Thompson's Waterleaf: Hydrophyllum capitatum var. thompsonii - Leaflets with entire margins or deeply lobed, the lobes directed forward. Flowers in a tight spherical ball. Flowers typically blue to lavender, occasionally white.
Fendler's Waterleaf, White-leaved Fendler's Waterleaf: Hydrophyllum fendleri var. albifrons (Synonyms: Hydrophyllum albifrons, Hydrophyllum congestum) - Leaflets with toothed margins. Inflorescence broader, somewhat umbrella-like. Leafblades noticeably longer than wide with 7-15 segments. Pedicels 2-7 mm long. Flowers typically white, lavander or purplish.
Pacific Waterleaf, Slender-stemmed Waterleaf: Hydrophyllum tenuipes (Synonym: Hydrophyllum viridulum) - Leaflets with toothed margins. Inflorescence broader, somewhat umbrella-like. Leaf blades about as wide as long with typically 5 segments (up to 9 segments could be present). Pedicels 5-12 mm long. Flowers in the Columbia River Gorge typically green or greenish-white to rarely creamy or lavender.