Delphinium (larkspur; family Ranunculaceae) A genus of annual or perennial herbs that have palmately lobed leaves and irregular flowers in racemes, comprising 5 petaloid sepals (the posterior one with a spur, giving the genus its common name), 4 petal nectaries, many stamens, and 1–3 follicles which form the fruit. Many Delphinium species are cultivated for their attractive flowers. There are about 250 species, found in the northern hemisphere.

del·phin·i·um / delˈfinēəm/ • n. a plant (genus Delphinium) of the buttercup family that bears tall spikes of typically blue flowers.

delphinium XVII. — modL. delphinium — Gr. delphī́nion larkspur, f. delphís, delphīn- DOLPHIN; so called from the dolphin-like form of the nectary.

delphinium (larkspur) Any of c.250 species of herbaceous plants native to temperate areas, with spirally arranged leaves and loose clusters of flowers. Petals form a tubular spur, which contains nectar. Garden delphiniums are varieties of Delphinium elatum. Family Ranunculaceae.