Lactuca virosa
bitter lettuce
Western, central, and southern Europe and North Africa
Overview
Lactuca virosa is a tall biennial or annual in the daisy family, sending up a stout, often purple-flushed stem 24-80 inches (60-200 cm) tall in its flowering year. The bluish-green leaves clasp the stem, with lobed, spine-edged margins and a row of stiff prickles along the midrib beneath; lower leaves are large and held more or less vertically. All parts exude a bitter white latex when cut, the source of the sedative preparation once called lactucarium. From July to September the branched upper stem carries many small pale-yellow flowerheads 0.4-0.5 inches (10-13 mm) across, each of strap-shaped ray florets, opening for part of the day. Seeds are flattened achenes, usually dark, topped with a white pappus for wind dispersal. The plant grows on disturbed ground, road verges, waste places, sea cliffs, and rough banks, usually on dry, sunny soils. In its first year it forms a leaf rosette, flowering and dying in the second. The bitter latex deters grazing, and the plant is mildly toxic if eaten in quantity.
Native Range
Native to western, central, and southern Europe and North Africa, reaching north to Britain. In Britain it grows mainly in England and Wales on dry, disturbed ground and coastal banks.Suggested Uses
Grown in wild, naturalistic, and pollinator plantings on dry, poor soils, and in collections of medicinal or historical herbs. Its height and bitter latex have long associated it with herbal use. The plant suits rough banks and waste-ground schemes where tall pioneers are wanted.How to Identify
Appearance
Size & Dimensions
Height2' - 6'8"
Width/Spread1' - 2'
Bloom Information
Flowerheads open from July to September on the much-branched upper stem. The small pale-yellow heads open in the morning and close by midday, pollinated by small bees and flies. After flowering each head produces wind-dispersed seed.
Detailed Descriptions
Foliage Description
bluish-greenGrowing Conditions
Sun Requirements
Requires 6-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight