Anderson's Larkspur

In much of its range Delphinium andersonii hybridizes occasionally with members of the D . nuttallianum complex and apparently with D . parishii in at least one site in California. These three taxa, with D . scaposum , form an interesting group in that they appear to be ecological replacements for one another, with D . parishii occupying arid, hot deserts to the south and southwest, D . andersonii growing in cooler, higher latitude and altitude deserts farther north, D . scaposum in cool deserts farther east, and D . nuttallianum at higher elevations in much of the geographic range of the other three species. Delphinium andersonii is often mistaken for D . nuttallianum . Most individuals of D . andersonii (roots much larger and more fibrous; stems solidly attached to roots; fruits long, narrow, erect; inflorescences usually longer and narrower at base; and pedicel sigmoid) can easily be distinguished from D . nuttallianum (roots smaller and not fibrous; stems tenuously attached to roots; fruits shorter, proportionally thicker, spreading; inflorescences relatively shorter and wider at base; and pedicel nearly straight).

Although roots of Delphinium andersonii are quite similar to those of D . antoninum , the two taxa may be readily distinguished by most features that separate D . nuttallianum from D . andersonii . The name Delphinium menziesii was misapplied to D . andersonii by S. Watson.

Stems (20-)30-60(-90) cm; base reddish, glabrous. Leaves mostly on proximal 1/2 of stem; green leaves usually present on proximal 1/5 of stem at anthesis; basal leaves 0-8 at anthesis; cauline leaves (0-)3-8 at anthesis; petiole 0.5-8 cm. Leaf blade round, 1.5-4 × 2-6 cm, nearly glabrous; ultimate lobes 5-30, width 2-8 mm (basal), 1-4 mm (cauline); lobe width of proximal leaves less than 4 mm. Inflorescences 10-25-flowered, cylindric; pedicel sigmoid (proximally spreading, distally ascending), 1-4(-6.8) cm, glabrous to puberulent; bracteoles 2-6(-8) mm from flowers, green, linear, 4-6(-11) mm, ± puberulent. Flowers: sepals dark blue, nearly glabrous, lateral sepals spreading to reflexed, 9-16 × 3-7 mm, spurs horizontal to slightly ascending, often decurved apically, 12-18 mm; lower petal blades elevated, ± exposing stamens, 4-8 mm, clefts 1-4 mm; hairs centered, mostly between claw and base of cleft, white. Fruits 17-32 mm, 4-5.5 times longer than wide, glabrous. Seeds: seed coat cells ± brick-shaped, cell margins ± undulate, surfaces smooth. 2 n = 16.

Calif., Idaho, Mont., Nev., Oreg., Utah.

Flowering late spring-early summer.

Talus, cold desert scrub, often growing up through shrubs, low places where snow collects; 1300-2000m.

Delphinium andersonii subsp. cognatum (Greene) Ewan

Delphinium andersonii is a species of perennial larkspur known as Anderson's larkspur. This wildflower is native to western North America, where it can be found in the Great Basin and the Sierra Nevada.

D. andersonii is an erect perennial usually reaching about half a meter in height. It has small leaves on long petioles with the leaf blades divided into long fingerlike lobes. The top of the slender stem is occupied by a cylindrical inflorescence of flowers, each flower two to four centimeters wide with a spur measuring nearly two centimeters in length. The flowers usually have sepals of a brilliant dark blue, with the lower two petals the same color and the upper two petals white. Some individuals have sepals and petals of very light purple or blue to almost white. The anthers are often yellow. It was named after Charles Lewis Anderson by Asa Gray.