Common Names: Ballhead Waterleaf, Thompson's Waterleaf, Thompson's Ballhead Waterleaf, Alpine Waterleaf

USDA lists 3 varieties:
var. thompsonii: (Thompson's Waterleaf) flowers are at or above the leaves. Found mainly in Columbia River Gorge.
var. capitatum: (Ballhead Waterleaf) flowers are below the leaves. Found throughout WA and upper wNA
var. alpinum: (Alpine Waterleaf) peducles often recurved, found in c OR, CA, NV, ID, CO.

Columbia River Gorge (CRG); east Central Cascades
TRAIL: Columbia Hills Natural Area Preserve; Umtanum Ridge
HABITAT: Shrub-steppe,
ELEVATION: 835 m (2,740 ft.); 580 m (1,900 ft.)
BLOOM TIME: 10-MAY; 22-APR