Uncaria tomentosa Seeds | Cat’s Claw
LATIN NAME: Uncaria tomentosa
COMMON NAME: Cat’s Claw
Plant Profile
Cat’s claw is a woody liana of the Amazon basin, climbing by means of paired, recurved hooks that form where the leaf stalks should be, hence the name. It scrambles up trees to twenty metres or more, with a slender, four-ridged stem, opposite oval leaves and small, tubular, cream-coloured flowers in tight round heads. The fruits are dry capsules that split to release winged seed. In the forest it prefers disturbed edges and riverbanks, where light reaches the understorey, and it can form dense tangles over several trees. Two species are gathered commercially, this one and Uncaria guianensis, and the bark of the stem is the part used. It is one of the best-known plants of Amazonian traditional medicine.
Science & Biotechnology
The chemistry of Uncaria tomentosa is built on oxindole alkaloids, which exist in two forms, tetracyclic and pentacyclic, that interconvert in solution and have different biological activity. The pentacyclic group, including mitraphylline and isomitraphylline, has been the focus of most pharmacological work, and extracts have shown immunomodulatory and anti-inflammatory effects in vitro and in animal models. Human trials are few and small, which is why regulatory bodies treat the claims cautiously. The plant also contains quinovic acid glycosides and procyanidins, and the bark is rich in tannins. A taxonomic complication is that some commercial material is Uncaria guianensis, which has a different alkaloid profile, so identity testing matters. The hooks themselves are modified branches, not thorns, and they are one of the characters used to separate species in the genus.
Uses & Benefits
The shredded bark is sold as a tea, a powder and a capsule, mostly for joint pain and for immune support, and it has a bitter, astringent taste that needs honey. In Peruvian and Brazilian folk practice it is used for inflammation, for digestive complaints and for recovery after illness. The root is also used, though the bark is preferred because harvesting root kills the plant. In the garden, cat’s claw is a curiosity for a large, warm conservatory, where it will climb a sturdy frame and flower in bright light. It is not a plant for a small space, and it needs high humidity to look well. Harvesting from the wild is regulated in Peru, and cultivated material is slowly becoming available.
Growing from Seed
Seed is scarce and short-lived, so sow as soon as it arrives. Use a light, sterile mix of peat, sand and perlite, surface-sow, and cover with a bare two millimetres, because light aids germination. Keep at twenty-five to thirty degrees and eighty per cent humidity; a propagator with bottom heat works. Germination takes two to five weeks. Pot on when the second pair of leaves opens, and give the seedling a small trellis at once, since the shoot wants to climb before it thickens. Grow on in filtered light with constant moisture and a free-draining compost. In cool climates keep it above fifteen degrees year round and mist daily.
Our Take
A rainforest liana with hooks, a bitter bark and a long medicinal record. It needs heat and a trellis, not a herb bed.
Related Reading
If Cat’s Claw appeals to you, these related plants are worth a look: