Valeriana rubra is a perennial plant, usually as a subshrub though it can take any form from a herbaceous plant to a shrub depending on conditions; the plants are usually woody at the base. The leaves are generally 5–8 cm in length. Their form changes from the bottom to the top of the plant, the lower leaves being petiolate while the upper leaves are sessile. The leaves grow in opposite pairs and are oval or lanceolate in shape. The plant flowers profusely, and though the individual flowers are small (no more than 2 mm), the inflorescences are large and showy. The flowers are small in rounded clusters each with 5 fused petals and a spur. The most typical color is a brick red or purplish red, but colors include deep crimson, pale pink, and lavender. Centranthus ruber 'Albus' (about 10% of individuals) has white blooms. Flowering takes place in early summer and, in cool summer areas, continues sporadically throughout the summer and into fall. The cultivar 'coccineus' is especially long-blooming. The blooms have a strong and somewhat rank scent. They are pollinated by both bees and butterflies and the plant is noted for attracting insects. It is used as a food plant by the larvae of some Lepidoptera species including angle shades. Seeds have tufts similar to dandelions that allow wind dispersal, and as such can self-seed freely and become invasive if not properly controlled.
