A variable species, five distinct varieties are recognized[].

Common Name:

General Information

Gaultheria leucocarpa is an erect evergreen shrub growing 50 - 200cm tall.
The plant is harvested from the wild and used in local medicine. The var Gaultheria leucocarpa yunnanensis is widely used medicinally in southern China, where it is known as 'tou gu cao', being valued especially for its rich content of salicylic acid[].

Known Hazards

The essential oil has GRAS (generally recognised as safe) status in America, when used in very small quantities[]. However, when it is taken in large amounts methyl salicylate (the main constituent of the oil) is toxic and causes problems similar to those caused by high doses of aspirin[].

Botanical References

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Range

E. Asia - southern China, Thailand, Cambodia, Laos, Vietnam, Malaysia, Indonesia and the Philippines.

Habitat

Montane forest and in open, exposed places among brushwood or shrubs at 500 - 3,300 metres[, ]. It is fairly common on the margins of craters, steep slopes, on stony, volcanic or sometimes peaty and generally poor soils[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Shrub
Height	1.50 m
Pollinators	Insects, Self
Self-fertile	Yes
Cultivation Status	Wild

Cultivation Details

A plant of higher elevations in the tropics, found at elevations of 500 - 3,000 metres[].
Prefers a moist but not boggy humus rich soil in shade or semi-shade[]. A peat and moisture loving species, it requires a lime-free soil[].
Plants can flower and fruit all year round in the tropics[].
Gaultheria leucocarpa yunnanensis (Franch.) T.Z.Hsu & R. C. Fang is the form most utilized for its salicylic acid in China[].
Plants in this genus are notably resistant to honey fungus[].

Edible Uses

Fruit - raw or cooked[]. The purplish-black, globose fruit is about 4 - 7mm in diameter[, ]. As with most Gaultherias, it is actually the swollen, fleshy calyx that is eaten[, ].

The leaves and flowers of several Gaultheria species yield wintergreen oil, which has an intensely sweet-aromatic, medicinal fragrance and flavour with a creamy-fruity top note and a sweet-woody dry-out. The oil was formerly used extensively to flavour drinks, its best known use is in root beers and cola drinks[]. Other products flavoured with wintergreen oil are candies, chewing gum and toothpaste[].

A herbal tea is made from the fermented leaves[].

Medicinal

A decoction of the rhizomes is used to resolve clots and bruising, stimulate blood circulation and promote bone-knitting and tissue repair[]. It is used in the treatment of liver cirrhosis, ascites, traumatic injuries, rheumatoid arthritis and pains in the joints and back[].

A leaf paste is applied externally to ease chest complaints, while in concoctions it is occasionally used as a prophylactic before and after childbirth[]. The leaves are used in traditional medicine to treat coughing, tuberculosis, fever and pain[].

The plant contains salicylic acid (the precursor to aspirin). This is known to have analgesic and antiinflammatory activity.
The main constituent of wintergreen oil is methyl salicylate, the oil from this species containing 96% methyl salicylate[]. Most plant parts contain methyl salicylate or its precursors. Fresh leaves and flowers have hardly any odour, but the characteristic odour becomes apparent when they are crushed and stored for a short time. Methyl salicylate is then formed by hydrolysis of glycosides. The oil contains minute quantities of alcohols and ketones.

The leaves and flowers of several Gaultheria species yield wintergreen oil. It is used medicinally, either as the extracted oil or as an infusion of the plant, in the treatment of rheumatism, neuralgia, sciatica and cancer and also for its carminative and anthelmintic properties. It is a mild antiseptic in mouth care products, e.g. against toothache and sore throat. It is applied in ointments and liniments for its anti-irritant properties.

Other Uses

The leaves and flowers of several Gaultheria species yield wintergreen oil, which has an intensely sweet-aromatic, medicinal fragrance and flavour with a creamy-fruity top note and a sweet-woody dry-out[]. In perfumery, traces of wintergreen oil may add natural notes to e.g. ylang-ylang, tuberose, narcissus, lily and gardenia[]. It is now rarely used in perfumery, however, because a cheap synthetic form of its main chemical component, methyl salicylate, is available[].
The oil is used to enhance the smell of finely cut leaves of Pandanus amaryllifolius Roxb. (rampeh) and to perfume clothes[].
The oil is also a component of insecticidal and insect repellent preparations[].
The essential oil is derived by steam distillation of the leaves[]. Prior to distillation the leaves are steeped in warm water to promote the enzymatic hydrolysis of glycosides to form methyl salicylate[].

The seeds are used in handicrafts[].

Propagation

The seed requires a period of cold stratification. Pre-chill for 4 - 10 weeks and then surface sow in a lime-free compost in a shady part of the greenhouse and keep the compost moist[]. The seed usually germinates well, usually within 1 - 2 months at 20°c, but the seedlings are liable to damp off. It is important to water them with care and to ensure that they get plenty of ventilation. Watering them with a garlic infusion can also help to prevent damping of[]. Prick out the seedlings into individual pots when they are about 25mm tall and grow them on in light shade in the greenhouse for at least their first winter[]. Plant them out in late spring or early summer. The seedlings are susceptible to spring frosts so might need some protection for their first few years outdoors. The leaves remain very small for the first few years[].
Cuttings of half-ripe wood 3 - 6cm long, July/August in a frame in a shady position. They form roots in late summer or spring[]. A good percentage usually take.
Division in spring just before new growth begins[]. Larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the spring.
Layering.