Polemonium caeruleum, known as Jacob's-ladder or Greek valerian, is a hardy perennial flowering plant. The plant produces cup-shaped, lavender-coloured or white flowers. It is native to temperate regions of Europe.
The plant usually reaches a height from 45 to 60 centimeters (18 to 24 inches), but some occasionally will be taller than 90 centimeters (35 inches.) The spread of the plant is also 45 to 60 centimeters. It can grow in North American hardiness zone 2.
The plant is native to damp grasslands, ...