Doubtful Knight's-spur: Delphinum ajacis (Synonyms: Consolida ajacis, Consolida ambigua, Delphinium ambiguum) -
Coast Larkspur, Low Larkspur: Delphinium decorum (Synonyms: Delphinium decorum ssp. decorum, Delphinium decorum var. decorum) -
Blue Mountain Larkspur, Slim Larkspur: Delphinium depauperatum (Synonyms: Delphinium cyanoreios, Delphinium diversifolium, Delphinium diversifolilum var. harneyense) -
Cliff Larkspur, Olympic Larkspur: Delphinium glareosum (Synonyms: Delphinium caprorum, Delphinium glareosum var. caprorum) - Columbia River Gorge specimens are now Delphinium basalticum.
Brown's Larkspur, Duncecap, Giant Larkspur, Hooker's Larkspur, Mountain Larkspur, Pale-flowered Larkspur, Sierra Larkspur, Tall Larkspur, Tower Larkspur, Western Larkspur: Delphinium glaucum (Synonyms: Delphinium occidentale, Delphinium scopulorum, Delphinium scopulorum ssp. occidentale, Delphinium scopulorum var. glaucum, Delphinium splendens) -
Pale Larkspur, White Rock Larkspur: Delphinium leucophaeum (Synonym: Delphinium nuttallii ssp. ochroleucum) -
Cliff Larkspur, Menzies' Larkspur: Delphinium menziesii (Synonyms: Delphinium menziesii ssp. menziesii, Delphinium menziesii ssp. pyramidale, Delphinium menziesii var. menziesii, Delphinium menziesii var. pyramidale) -
Orange Larkspur, Red Larkspur: Delphinium nudicaule -
Thin-petal Larkspur, Two-lobe Larkspur, Upland Larkspur: Delphinium nuttallianum (Synonyms: Delphinium bicolor, Delphinium decorum ssp. tracyi, Delphinium lineapetalum, Delphinium menziesii ssp. utahense, Delphinium menziesii var. utahense, Delphinium nelsonii, Delphinium nuttallianum var. fulvum, Delphinium nuttallianum var. levicaule, Delphinium nuttallianum var. lineapetalum, Delphinium nuttallianum var. nuttallianum, Delphinium pauciflorum, Delphinium sonnei) -
Nuttall's Larkspur: Delphinium nuttallii (Synonym: Delphinium nuttallii ssp. nuttallii) -
Willamette Valley Larkspur: Delphinium oreganum -
Peacock Larkspur: Delphinium pavonaceum (Synonym: Delphinium menziesii ssp. pallidum) -
Anderson's Larkspur: Delphinium scaposum var. andersonii (Synonyms: Delphinium andersonii, Delphinium andersonii ssp. andersonii, Delphinium andersonii ssp. cognatum)
Cow Poison, Cow-poison, Poison Larkspur: Delphinium trolliifolium -