Thin Petal Larkspur

Delphinium lineapetalum

General: Perennial from somewhat fleshy and tuberous roots, the stems 1.5-4 dm. tall, usually single and simple.
Leaves: Leaves few, long-petiolate, mostly basal, the blades 2-6 cm. broad, 2-4 times parted or lobed into linear or oblong-lanceolate segments 1.5-5 mm. broad; cauline leaves much reduced upward.
Flowers: Inflorescence simple or compound, the racemes 3-15 flowered; the lower pedicels several times as long as the flowers, spreading or ascending; sepals 5, pale blue, widely spreading, 17-25 mm. long, the lower pair the largest; the spur 13-20 mm. long, from about as long to twice as long as the top sepal; petals 4, pale blue to white, very prominently lined with purplish-black, the blade small, shorter than the claw; stamens numerous; pistils 3.
Fruits: Follicles 15-22 mm. long, somewhat spreading.
Thin petal larkspur Getting good photos of these incredibly oddly shaped flowers can be challenging.. in this one I was lucky enough to get a bonus spider - Mecaphesa sp. (from eye arrangement and hairs) maybe Mecaphesa importunus - similar markings and known to the area. Delphinium lineapetalum,Thin Petal Larkspur

Appearance

General: Perennial from somewhat fleshy and tuberous roots, the stems 1.5-4 dm. tall, usually single and simple.
Leaves: Leaves few, long-petiolate, mostly basal, the blades 2-6 cm. broad, 2-4 times parted or lobed into linear or oblong-lanceolate segments 1.5-5 mm. broad; cauline leaves much reduced upward.
Flowers: Inflorescence simple or compound, the racemes 3-15 flowered; the lower pedicels several times as long as the flowers, spreading or ascending; sepals 5, pale blue, widely spreading, 17-25 mm. long, the lower pair the largest; the spur 13-20 mm. long, from about as long to twice as long as the top sepal; petals 4, pale blue to white, very prominently lined with purplish-black, the blade small, shorter than the claw; stamens numerous; pistils 3.
Fruits: Follicles 15-22 mm. long, somewhat spreading.
thin petal larkspur  Delphinium lineapetalum,Geotagged,Spring,Thin Petal Larkspur,United States

Distribution

Endemic to Washington, primarily found in the Wenatchee Mountains of Chelan and Kittitas Counties in Washington.
Thin Petal Larkspur  Delphinium lineapetalum,Geotagged,Spring,Thin Petal Larkspur,United States

Habitat

Meadows and forest openings in foothills and valleys.

References:

Some text fragments are auto parsed from Wikipedia.

http://biology.burke.washington.edu/herbarium/imagecollection.php
Taxonomy
KingdomPlantae
DivisionAngiosperms
ClassEudicots
OrderRanunculales
FamilyRanunculaceae
GenusDelphinium
SpeciesDelphinium lineapetalum