Lactuca perennis aka Blue Lettuce

Lactuca perennis is a perennial in the daisy family, Asteraceae. Gardeners know it as perennial lettuce or blue lettuce. Kew lists Spain as its native range. Plants For A Future records it across much of Europe. Its listed range includes France, Italy, Germany, and the Balkans. The RHS says it is not native to Britain or Ireland. It grows in temperate climates and occurs in rocky, dry places. These sites often have lime-rich soil.

Plants reach about 2 feet (0.6 metres) tall. Their spread is about 1 foot (0.3 metres). They form clumps that spread only a short distance. This modest size suits a cultivated bed with enough sun. The supplied species account gives few details about leaf or stem shape. It does describe leaves that people can harvest for food. Their taste changes with the season and the flowering stage.

Flowers appear from June to August, according to Plants For A Future. Each flower has both male and female organs. Insects pollinate the flowers, and the plant is self-fertile. Seeds ripen from July through September, overlapping with the flowering season. The evidence does not describe the species’ flower shape or fruit. Genus-wide flower details do not establish those traits for this species.

Choose a sunny site with soil that drains well. Plants For A Future recommends a light sandy loam. Sandy and loamy soils both suit it. It accepts mildly acid, neutral, and mildly alkaline ground. Soil may be dry or moist, but shade does not suit it. The same source reports cold tolerance near −13°F (−25°C). It lists USDA zones 5–9 and says frost does not harm it. Propagation options include seed, spring division, and spring root cuttings. Sow seed in April under glass, with a thin soil cover. Keep young seedlings under glass through their first winter. Plant them out after the last expected frost.

The leaves can be eaten raw or cooked. They taste milder in late winter and spring. Blanching can help reduce their bitterness. Summer leaves become more bitter as flowering begins. The supplied account gives no species-specific toxicity report. Its medicinal discussion relies on claims about the wider genus. Those claims do not establish this plant’s safety or medicinal effects.