Palicourea colorata Seeds | Palicourea
LATIN NAME: Palicourea colorata
COMMON NAME: Palicourea, Psychotria colorata
Plant Profile
Palicourea colorata is an Amazonian understorey shrub known as perpetua do mato, and it is one of the few plants with a painkiller that works like morphine. It grows in the secondary forest and forest edges of the Amazon basin, from the Guianas through Para and Maranhao, usually in the shade of taller trees on soils that are acid and poor. The plant is a slender shrub of one to three metres, with opposite leaves, reddish young growth and small white flowers in terminal clusters, followed by dark fleshy fruits. Every part of it is bitter and slightly numbing, and the leaves and flowers are the parts used in the home remedies of the caboclo communities, who make a tea for pain. The Ka’apor of Maranhao use the fruit as bait when fishing for small characins, and they rub the leaves between the hands in a coming-of-age practice. It is a plant with a long record of use and a short record of study.
Science & Biotechnology
Psychotria colorata, as it was long known, contains pyrrolidinoindoline alkaloids, and two of them explain its reputation: hodgkinsine, which acts as both a mu-opioid agonist and an NMDA antagonist, and psychotridine, which is an NMDA antagonist with little opioid affinity. Animal studies in the 1990s showed that an alkaloid extract produced dose-dependent analgesia which naloxone reversed, strong evidence for an opioid mechanism, and binding studies confirmed an effect on opioid receptors in rat brain tissue. The same work found that the quinoline alkaloids in the plant were inactive, so the activity sits in a specific structural class. The genus is being reorganised: many species once placed in Psychotria are now in Palicourea, and the combination Palicourea colorata reflects that shift. The plant is a forest understorey species and depends on shade and on bird dispersal of its fruit, and it is not a crop.
Uses & Benefits
The leaves and flowers are used in Amazonian folk medicine as a painkiller, taken as a tea for headaches, toothache and stomach pain, and the plant is the main ingredient of a remedy that has been studied in the laboratory rather than in the clinic. The fruit is used by the Ka’apor as bait for small fish, and the leaves feature in a ritual practice connected with learning to make cassava presses. In the wider region the plant is used for fevers and for skin complaints. It has no food value and no timber value, and its medicinal use carries real risk, since the alkaloids are active on the central nervous system and the dose in a home preparation is unknown. For gardeners in the tropics it is a shade-loving shrub with modest flowers and a place in a medicinal or ethnobotanical collection. It is not a plant to self-medicate with, and it should not be given to children.
Growing from Seed
Sow fresh seed, cleaned of pulp, in a shaded pot of leafmould, loam and grit, at 22 to 28 degrees; germination is slow and can take two to three months. Keep the seedlings humid and out of direct sun, and pot them on as they grow. Plant out in deep shade in acid, well-drained soil rich in organic matter, and mulch with leaf litter. Water regularly but never let the roots stand in water. The plant is tender below about ten degrees and needs a frost-free climate or a heated glasshouse. Prune lightly after flowering to keep it bushy, and feed with a slow-release fertiliser for acid-loving plants in spring. It is not a long-lived shrub in cultivation, so take cuttings from semi-ripe wood in summer to keep it going.
Our Take
An Amazonian shrub with an alkaloid that behaves like an opioid, used for pain long before anyone studied it. Shade, warmth, and no experiments.
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