Herbs & Plants

Lactuca formosana

Botanical Name:
Lactuca formosana
Family :
Class :

Common Names: Lactuca morii Hayata; L. sonchus H. Léveillé & Vaniot; Pterocypsela formosana (Maximowicz) C. Shih; P. sonchus (H. Léveillé & Vaniot) C. Shih.

Lactuca formosana is native to E. Asia – China. It grows in grasslands on mountain slopes and in valleys, thickets or forests on mountain slopes, fields, along trails; 100-2000 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Ningxia, Shaanxi, Sichuan, Taiwan, Yunnan, Zhejiang.


Lactuca formosana is an annual or perennial herb 0.5-1.5 m tall. Roots ramose. Stem solitary, erect, loosely branched apically, ± hirsute, glabrescent. Lower and middle stem leaves with narrow petiole-like amplexicaul basal portion to 5 cm or with conspicuously expanded and semiamplexicaul base; leaf blade elliptic, lanceolate, or oblanceolate, 8-18 × 4-8 cm, hirsute, main rib echinulate, undivided and with coarsely dentate margin or pinnatifid with 2-5 pairs of elliptic to broadly falcate lateral lobes, faintly to strongly dentate on margin, and a lanceolate or triangular terminal lobe. Upper stem leaves similar to middle stem leaves, margin mostly ± entire. Synflorescence loosely corymbose, with ca. 10 to many capitula. Capitula with usually 25-30 florets. Involucre cylindric, 1-1.1 cm at anthesis, to 1.8 × 0.8 cm in fruit. Phyllaries acute to acuminate at apex; outer phyllaries broadly obovate to lanceolate, longest ca. 8 × 1-2 mm; inner phyllaries 8. Florets yellow. Achene 4.5-6.5 mm; body reddish brown, dark brown, or blackish brown, ellipsoid, compressed, broadly winged, 2-2.3 mm wide, with 1 prominent rib on either side, apically contracted into a usually pale to greenish filiform 2-3.5 mm beak. Pappus 7-8 mm, caducous. Fl. and fr. Apr-Nov.

The flowers are hermaphrodite (have both male and female organs) and are pollinated by Insects.Suitable for: light (sandy) and medium (loamy) soils and prefers well-drained soil. Suitable pH: acid, neutral and basic (alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.
We have very little information on this species and do not know if it will be hardy in Britain, though judging by its native range it could succeed outdoors in many parts of this country. We are not sure if it is an annual or perennial but assume that it can be grown as a spring-sown annual. The following notes are based on the general needs of the genus. Prefers a light sandy loam.

Seed – sow spring in situ and only just cover the seed. Germination is usually fairly quick.

Edible Uses: Leaves – cooked. A famine food, they are only used when all else fails.

Medicinal Uses:
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.

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 but is produced when the plant starts to go to seed.

Disclaimer : The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplement, it is always advisable to consult with your own health care provider.


Lactuca debilis