Stems (25-)50-80(-100) cm; base reddish, not longitudinally ridged, variably puberulent. Leaves mostly cauline at anthesis; basal leaves 0-3 at anthesis; cauline leaves 2-13 at anthesis; petiole 1-19 cm, petioles of proximal leaves ± long-pubescent. Leaf blade round to pentagonal, 1-6 × 1.5-10 cm, puberulent; ultimate lobes 3-17, width 4-16(-25) mm (basal), 1-8(-19) mm (cauline). Inflorescences (2-)7-20(-31)-flowered, open; pedicel 1-4(-6) cm, puberulent; bracteoles (2-)8-12 mm from flowers, green, linear, 3-6(-9) mm, puberulent. Flowers: sepals dark bluish purple, puberulent, lateral sepals spreading, (12-)14-19(-24) × 7-12(-15) mm, spurs ascending, decurved apically, 11-19 mm; lower petal blades slightly elevated, mostly covering stamens, 5-10 mm, cleft 2-3 mm; hairs sparse, mostly on inner lobes, absent on margins, white. Fruits 9-21 mm, 2.5-4.2 times longer than wide, sparsely puberulent. Seeds not echinate, ± smooth to naked eye; seed coat cells with margins ± undulate, surfaces smooth.
Flowering spring. Coastal chaparral, clearings in coniferous woods; of conservation concern; 0-400 m; Calif.
Delphinium hutchinsoniae is known from only a few populations near Monterey and south to the Big Sur region. Hybrids have been produced between D . hutchinsoniae and D . cardinale grown in a common garden. Hybrids also occur with D . parryi subsp. maritimum .
Delphinium hutchinsoniae is similar, and probably closely related, to D . variegatum . The two may be distinguished by the decurved spur of D . hutchinsoniae ; the spur of D . variegatum is normally straight (or decurved nearer apex). Delphinium hutchinsoniae lacks marginal hairs on lower petals; such hairs are present in D . variegatum . The two species are also geographically separated.