Common Name: Indian Lettuce

General Information

Lactuca indica is an erect, perennial plant forming a rosette of basal leaves and a rarely-branched stem up to 120cm tall from a taproot.
The plant is harvested from the wild for local use as a food and a medicine. It is sometimes cultivated for its edible leaves in parts of Asia, especially Malaysia, Indonesia, the Philippines, Taiwan and Japan[, , ], and the leaves are sometimes sold in local food markets[]..

Known Hazards

Although no specific mention of toxicity has been seen for this species, many plants in this genus contain a narcotic principle, this is at its most concentrated when the plant begins to flower. This principle has been almost bred out of the cultivated forms of lettuce (Lactuca sativa), but is still produced when the plant starts to go to seed[].

Botanical References

,

Range

E. Asia - Russian Far East, eastern and southern China, Japan, Korea, northeastern India, Vietnam, Laos, Thailand.

Habitat

Grassy places in lowland all over Japan[]. This report refers to the sub-species L. indica laciniata. (O.Kuntze.)Hard. The plant is found at elevations from near sea level to 2,000 metres[].

Properties

Edibility Rating
Medicinal Rating
Habit	Perennial
Height	1.20 m
Pollinators	Insects
Cultivation Status	Cultivated, Wild

Cultivation Details

Prefers a light sandy loam.
We do not know how hardy this plant will be in Britain, though it can be grown here as an annual. It takes about 60 days from seed sowing until the first leaves are harvested[].
This species is sometimes cultivated for its edible leaves in Asia[, ]. It originated in China but is now cultivated in many parts of S.E. Asia[].

Edible Uses

Leaves - raw or cooked[, , ]. Added to salads or soups[]. They have a slightly bitter flavour[]. The leaves contain about 1.5% protein, 0.4% fat, 2.2% carbohydrate, 0.7% ash[].
Stem - cooked[]. It contains 0.6% protein, 0.1% fat, 2.1% carbohydrate, 0.5% ash[].

Medicinal

The plant is digestive and tonic[].
Although we have seen no specific reports for this species, most if not all members of the genus have a milky sap that contains the substance 'lactucarium' and can probably be used as the report below details[].

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[]. The sap contains 'lactucarium', which is used in medicine for its anodyne, antispasmodic, digestive, diuretic, hypnotic, narcotic and sedative properties[, , , , , , ]. Lactucarium has the effects of a feeble opium, but without its tendency to cause digestive upsets[], nor is it addictive[]. It is taken internally in the treatment of insomnia, anxiety, neuroses, hyperactivity in children, dry coughs, whooping cough, rheumatic pain etc[]. Concentrations of lactucarium are low in young plants and most concentrated when the plant comes into flower[]. 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[]. An infusion of the fresh or dried flowering plant can also be used[].
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[] and overdoses can cause death through cardiac paralysis[, ].
Some physicians believe that any effects of this medicine are caused by the mind of the patient rather than by the medicine[].
The sap has also been applied externally in the treatment of warts[].

Other Uses

An extract of the whole plant is used as an ingredient in commercial cosmetic preparations as a skin conditioner[].

Propagation

Seed - sow early spring in a warm greenhouse, only just covering the seed. Germination is usually rapid, prick out the seedlings when large enough to handle and plant them out after the last expected frosts[].
Division in spring. Make sure each piece of root has a leaf bud[].
Root cuttings in late winter[].