Echium plantagineum aka Purple Viper's Bugloss

Echium plantagineum belongs to the borage family, Boraginaceae. Names include Paterson's curse, Salvation Jane, and purple viper's bugloss. It grows as an annual or a biennial. Its native range spans Europe, North Africa, and western Asia. It also includes several Atlantic and Mediterranean islands. It grows wild in southwest England. Beyond its native range, it inhabits fields, roadsides, and disturbed ground.

Garden plants reach about 1.6–3.3 feet [0.5–1 metre] tall. RHS also describes plants reaching 2.5 feet [0.75 metres]. PFAF gives a shorter height of 2 feet [0.6 metres]. Spread ranges from 0.3–1.6 feet [0.1–0.5 metres]. The plant grows fast and starts with a leaf rosette. Its green leaves feel soft and bear hairs. They have smooth edges and oval or reversed lance shapes. Leaves alternate along the stems above the rosette. Plants may have one stem or several upright stems. Stiff hairs cover these green stems.

Flowers appear in spring and summer, with timing varying by source. RHS describes pink buds opening into purple flowers. NC State records blue flowers that turn purple, then pink. The flowers have a trumpet or funnel shape. They cluster on one side of the stem without stalks. Each flower has five stamens, with two longer than the rest. Fruits contain four small, oval nutlets with three angles. Their surfaces have pits and wrinkles. Nutlets may be gray, brown, or black.

Grow this plant in full sun and moderately fertile soil. NC State also lists partial shade as suitable. It accepts clay, loam, sand, and chalk. Soil may be acid, neutral, or alkaline. It needs good drainage and suits moist, well-drained ground. RHS rates its UK hardiness as H4. NC State lists USDA zones 3b through 8b. Grow new plants from seed; pruning is not needed. RHS suggests borders, slopes, coastal sites, and wildlife gardens. It reports few pest or disease problems.

Its spread can outweigh its value as a garden flower. It invades parts of Australia, South Africa, and the United States. Heavy seed production lets it crowd out other plants. Birds, livestock, weather, and equipment move its seeds. Leaves and stems can irritate human skin. Handling may also trigger hay fever. Its alkaloids poison grazing animals, with horses at high risk. Fresh plants and contaminated hay can cause fatal liver damage. PFAF discusses seed oil for food and cosmetic use. That use does not establish that raw seeds are safe to eat.