Polemonium coeruleum (larkspur) is a perennial herbaceous plant up to 150 cm tall, usually reaching 80–100 cm in garden conditions. The stems are leafy, hollow and smooth; the leaves are large, bipinnate, lanceolate-shaped, with their number ranging from 15 to 27 per stem. Blue or purple flowers have a diameter of up to 1.5 cm, flat-bell shaped form and are collected in terminal panicle inflorescences up to 15 cm long. The plant blooms in June–July for 45–50 days and withstands low temperatures down to ‑35 °C, which makes it suitable for growing in cool regions.
Polemonium prefers semi-shady places with moist air and light, damp soils. Caring for the plant is simple: after flowering, all shoots are cut off to stimulate the growth of new ones. The plant is well suited for planting in groups, mixborders and as a decorative element at the second plane of the site. If desired, its cutting can be used.
The medicinal raw materials of Polemonium are rhizomes and roots, which are harvested in autumn, washed and dried at a temperature not exceeding 30–60 °C. The plant contains triterpenoid saponins (up to 30 %), resins, essential oils, organic acids, fats, starch, as well as trace elements such as iron and silver. Due to these components, Polemonium has a strong sedative effect that is 8–10 times higher than the effect of valerian. In addition, the plant has antitussive, expectorant, hemostatic and disinfecting effects, and is used in chronic bronchitis, pulmonary tuberculosis, cough, insomnia, epilepsy, increased nervous excitability and other conditions. In folk medicine, Polemonium is used both internally and as decoctions for treating respiratory diseases and nervous tone.
