Wild Lettuce, Bitter lettuce

Lactuca virosa

Physical Characteristics

Lactuca virosa is a ANNUAL/BIENNIAL growing to 1.8 m (6ft). See above for USDA hardiness. It is hardy to UK zone 6 and is not frost tender. It is in flower from July to September, and the seeds ripen from August to September. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. Suitable for: light (sandy) and medium (loamy) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers moist soil.

Distribution

Europe, including Britain, from Belgium south and west to N. Africa, Central Russia and W. Asia.

Habitats

Cultivated Beds;

Edible Uses

Edible Parts: Leaves Oil Edible Uses: Oil Leaves - raw or cooked[52]. Very tender[5]. Caution is advised, see the notes above on toxicity. A mild flavoured oil, used in cooking, is obtained from the seeds[4].

Medicinal Uses

Anodyne Antispasmodic Digestive Homeopathy Hypnotic Narcotic Sedative Tonic Urinary The whole plant is rich in a milky sap that flows freely from any wounds. This hardens and dries when in contact with the air[4]. The sap contains 'lactucarium', which is used in medicine for its anodyne, antispasmodic, digestive, diuretic, hypnotic, narcotic and sedative properties[9, 21, 46, 165, 192, 213, 238]. Lactucarium has the effects of a feeble opium, but without its tendency to cause digestive upsets[4], nor is it addictive[7]. It is taken internally in the treatment of insomnia, anxiety, neuroses, hyperactivity in children, dry coughs, whooping cough, rheumatic pain etc[238]. Concentrations of lactucarium are low in young plants and most concentrated when the plant comes into flower[238]. It is collected commercially by cutting the heads of the plants and scraping the juice into china vessels several times a day until the plant is exhausted[4]. This species is probably the richest supply of lactucarium[4]. The plant also contains 'hyoscyamine', a powerful depressant of the parasympathetic nervous system[213]. An infusion of the fresh or dried flowering plant can also be used[9]. The plant should be used with caution, and never without the supervision of a skilled practitioner. Even normal doses can cause drowsiness whilst excess causes restlessness[238] and overdoses can cause death through cardiac paralysis[7, 9]. Some physicians believe that any effects of this medicine are caused by the mind of the patient rather than by the medicine[213]. The sap has also been applied externally in the treatment of warts[222]. A homeopathic remedy is made from the plant[9]. It is used in the treatment of chronic catarrh, coughs, swollen liver, flatulence and ailments of the urinary tract[9].

Known Hazards

Poisonous[7, 19]. Cases of poisoning caused by this plant have only been recorded very rarely[65].