Polemonium aka Jacob's Ladder

Polemonium, commonly known as Jacob's ladders or Jacob's-ladders, is a genus of flowering plants in the family Polemoniaceae. There are between 25 and 40 species of Polemonium, native to cool temperate to arctic regions of the Northern Hemisphere, with one species found in the southern Andes in South America. Many of these plants thrive in high altitude, mountainous areas. The plants are perennial, although some species can be annual, and they can grow anywhere from 10 to 120 cm tall. They have bright green leaves that are divided into lance-shaped leaflets. In spring and summer, they produce blue, white, or pink flowers. Some species of Polemonium serve as food plants for the larvae of certain Lepidoptera species, including Coleophora polemoniella. One specific species within the Polemonium genus is Polemonium caeruleum, also known as Jacob's-ladder or Greek valerian. This hardy perennial plant has cup-shaped, lavender-colored or white flowers. It is native to temperate regions of Europe and can grow up to 0.4 m in height. Polemonium caeruleum blooms from June to July, and its seeds ripen in July. It is hermaphroditic and attracts bees for pollination. This species prefers well-drained soil with a suitable pH range of acid, neutral, or basic. It can tolerate semi-shade or no shade but thrives in moist soil.