Quassia amara (amargo, bitter-ash, bitter-wood)
Category: Medicines - plant based
Introduction and description
Quassia amara (amargo, bitter-ash, bitter-wood) is a species in the genus Quassia, with some botanists treating it as the sole species in the genus. The genus was named by Carolus Linnaeus who named it after the first botanist to describe it: the Surinamese freedman Graman Quassi.
Q. amara is native to Costa Rica, Nicaragua, Panama, Brasil, Peru, Venezuela, Suriname, Colombia, Argentina, French Guiana and Guyana. Q. amara is widely planted outside its native range.
Q. amara is used as insecticide in traditional medicine and as additive in the food industry.
Quassia amara is a shrub or rarely a small tree, growing to 3 m tall (rarely 8 m). The leaves are compound and alternate, 15–25 cm long, and pinnate with 3-5 leaflets, the leaf rachis being winged. The flowers are produced in a panicle 15–25 cm long, each flower 2.5-3.5 cm long, bright red on the outside, and white inside. The fruit is a small drupe 1-1.5 cm long.
The bark contains the chemical quassin - one of the most bitter substances found in nature and the one which gives the plant its alternative name of Bitter wood.
Seeds and cuttings can be used for propagation of Q. amara. Frost is not tolerated, but the plant is partially drought tolerant. A large amount of indirect light is recommended.
Extracts of Quassia wood or bark act as a natural insecticide. “For organic farming this is of particular interest”. Good protection has been shown against a number different insect pests e.g. aphids, Colorado potato beetle, Anthonomus pomorum, Rhagoletis cerasi, and the Caterpillars of Tortricidae. Quassin extract works as a contact insecticide.
“Adverse effects on beneficial organisms have not been found”.
Around 200 grams of Quassia wood chips are put together with 2 liters of water. It is allowed to stand for 24 hours and then it is cooked for 30 min. It is then diluted with 10 to 20 liters of water and used as a spray The use of approximately 3-4.5 kg wood extract per hectare seems to be optimal to minimize the damage of Hoplocampa testudinea on apple trees.
For Switzerland, a licensed formulation is available for organic farming.
Other research [see observations] shows it has much more general anti-parasitic action – for external use. It has been used traditionally against hair parasites (lice, fleas) and Mosquito larvae in ponds, where it appears to do no harm to the fishes.
The component Simalikalactone D was identified as an antimalarial. The preparation of a tea out of young leaves [not the bark] is used traditionally in French Guyana. Experiments showed a high inhibition of Plasmodium yoelii yoelii and Plasmodium falciparum.
- Dr Duke's list of Chemicals and their Biological Activities in: Quassia amara L. (Simaroubaceae) -- Bitterwood, Quassia, Amargo 019145
- Dr Duke's list of Chemicals in Plants with Amoebicide Activity of high potency 019143
- Efficacy of topical 4% Quassia amara gel in facial seborrheic dermatitis:a randomized, double-blind, comparative study 019147
- New findings on Simalikalactone D, an antimalarial compound from Quassia amara L 019148
- Simalikalactone D is responsible for the antimalarial properties of an amazonian traditional remedy made with Quassia amara 019146