Delphinium carolinianum ssp. virescens (Nutt.) R.E. Brooks

Prairie Larkspur


CC = 6
CW = 5
MOC = 35

© DETenaglia

Family - Ranunculaceae

Habit - Rhizomatous perennial forb, the roots fibrous, sometimes relatively stout, not tuberous.

Stems - Erect, single, to 90 cm, moderately to densely short-hairy, less commonly with longer hairs, some of the hairs usually gland-tipped.

Delphinium_carolinianum_ssp_virescens_stem.jpg Stem and nodes.

© SRTurner

Leaves - Alternate, deeply palmately divided, petiolate below to nearly sessile above. Basal rosette often absent at flowering. Stem leaves 5-12 above the rosette. Petioles of the uppermost stem leaves 6-13 mm long. Leaf blades 2.2-7.5 cm long, 4.5-11.0 cm wide, the deepest divisions reaching the blade base, the ultimate segments 1-3 mm wide, linear or narrowly oblanceolate, angled to a bluntly or sharply pointed tip or rounded with an abrupt, minute, sharply pointed tip.

Delphinium_carolinianum_ssp_virescens_leaves2.jpg Stem and leaves.

© SRTurner

Delphinium_carolinianum_ssp_virescens_leaf1.jpg Mid-upper stem leaf.

© SRTurner

Delphinium_carolinianum_ssp_virescens_leaves.jpg Pressed leaves.

© DETenaglia

Inflorescences - Narrow terminal racemes, the axis moderately to densely pubescent with minute curled hairs, the flower stalks erect or nearly so, appearing more or less appressed to the inflorescence axis, at least in the lower half of the inflorescence, the lowermost stalks 1.2-3.3 cm long, the bracts subtending the flower stalks all undivided or occasionally the lowermost 3-parted.

Delphinium_carolinianum_ssp_virescens_inflorescence.jpg Inflorescence.

© SRTurner

Flowers - Sepals pale to deep blue, purple to white, or greenish, the lateral sepals 7-15 mm long, the spur 12-17 mm long, slightly curved upward, rugose. Corollas of 4 free petals, these with the body 4.5-7.5 mm long, white, but often purplish-or bluish-tinged, the lower pair 2-lobed to about the midpoint, bearded on the inner surface. Stamens numerous, surrounding the pistils. Filaments glabrous, greenish-white, compressed, to 6 mm long, some curled, others straight. Anthers olive-greenish brown, 1.8-2.0 mm long. Pistils usually 3.

Delphinium_carolinianum_ssp_virescens_flowers2.jpg Flowers.

© SRTurner

Delphinium_carolinianum_ssp_virescens_flower.jpg Flower.

© DETenaglia

Delphinium_carolinianum_ssp_virescens_flower2.jpg Flower and leafy bract.

© SRTurner

Fruits - Follicles 10-19 mm long, erect, those developing from a given flower more or less parallel, glabrous or finely short-hairy. Seeds 1.4-2.0 mm long, the outer surface appearing scaly, yellowish brown to brown.

Delphinium_carolinianum_ssp_virescens_fruits.jpg Fruits.

© SRTurner

Flowering - May - June.

Habitat - Upland prairies, glades, tops of bluffs, savannas, forest openings, railroads, roadsides.

Origin - Native to the U.S.

Lookalikes - D. carolinianum ssp. carolinianum, D. treleasei, D. exaltatum.

Other info. - This attractive species is found in Missouri in scattered counties predominantly on the western side of the state. Although this white-flowered subspecies may be a bit less common in Missouri than the blue-flowered form (ssp. carolinianum), it has a wider range overall, comprising a wide band in the central part of the continental U.S. It does not occur at all in either of the Carolinas. The plant is easily recognized by its wand-like inflorescences of interesting flowers, which are normally white and held near the central inflorescence axis on short stalks. The flowers often have a somewhat disheveled appearance. Two additional subspecies are commonly recognized in regions to our south and east.

Plants in the Delphinium genus often contain alkaloids of an interesting and structurally complex class. In D. carolinianum these include the compounds delcaroline, ajaconine, and browniine. An alcoholic extract of the seeds has been used to kill head lice. However, the plants are toxic to both humans and livestock. Cattle find it palatable and have been poisoned by grazing and also by hay which is contaminated by the plants.

Photographs taken in Lebanon, TN., 5-16-03, and at Taberville Prairie, MO., 6-7-03 (DETenaglia); also along a roadside in Gray County, KS, 6-4-2016, and at Tallgrass Prairie National Preserve, Chase County, KS, 6-5-2016 (SRTurner).