Valley larkspur, recurved larkspur

Delphinium hesperium A. Gray var. recurvatum (Greene) K. C. Davis

Stems (18-)30-50(-85) cm; base reddish, glabrous. Leaves: basal leaves 0-2 at anthesis; cauline leaves 3-7 at anthesis; petiole 1-8 cm. Leaf blade round to pentagonal, 1-4 × 1.5-6 cm, nearly glabrous; ultimate lobes 3-11, width 3-15 mm (basal), 1-10 mm (cauline). Inflorescences (8-)10-25(-47)-flowered, narrowly pyramidal; pedicel ± spreading, (0.5-)1.5-4(-6) cm, nearly glabrous; bracteoles 3-8(-18) mm from flowers, green, sometimes margins white, lanceolate to linear, 3-5(-8) mm, nearly glabrous. Flowers: sepals light to sky blue (becoming bluer upon drying), puberulent, lateral sepals reflexed, 11-16 × 5-7(-9) mm, spurs straight to gently upcurved, ascending 0-30° above horizontal, 10-15(-18) mm; lower petal blades elevated, ± exposing stamens, 5-8 mm, clefts 0.5-2.5 mm; hairs mostly centered on inner lobes near base of cleft, white. Fruits 8-21 mm, 2.2-3 times longer than wide, puberulent. Seeds: seed coat cells brick-shaped, cell margins undulate, surfaces roughened. 2 n = 16.

Flowering spring. Grassland, Atriplex scrub; of conservation concern; 30-600 m; Calif.

Delphinium recurvatum has a very restricted distribution in the Central (especially San Joaquin) Valley. This species was probably much more common in the past; most of its habitat has been converted into irrigated croplands. Delphinium recurvatum grows in poorly drained, alkaline soils on valley floors.

Hybrids are known between Delphinium recurvatum and D . gypsophilum , D . hesperium , D . parryi , and D . variegatum . Delphinium recurvatum is most likely to be confused with D . gypsophilum or D . hesperium subsp. pallescens . Distinguishing features are found in discussions of those taxa.