Cat’s Claw ~ Uña de gato Plant Care Guide
Uncaria tomentosa (popularly known in English as Cat’s Claw, although that name is also used for various other plants; in Spanish as Uña de Gato or as the name given by Roman Warszewski Vilcacora) is a woody vine found in the tropical jungles of South and Central America, which derives its name from its claw-shaped thorns. It is used as an alternative medicine in the treatment of a variety of ailments. Other common names include: hawk’s claw, pot hook, and sparrowhawk nail.
Cat’s claw is sometimes cultivated or managed in tropical forests of South America. U. guianensis may be cultivated in secondary forests with full sunlight, but U. tomentosa requires more shade, as it is found more often in primary forest. U. tomentosa primarily grows naturally in the following Holdridge life zones: tropical (bh-T and bmh-T), premontane tropical (bh-PT and bmh-PT), and the subtropical forest (bh-S). U. tomentosa prefers the following soil types: Ortic Acrisols, Distric Cambisols and Fluvisols; soil texture: 34–76% sand, 20–40% silt, and 4–38% clay; and a pH of 5.2–7.7. U.guianensis is primarily found in the following Holdridge life zones: tropical (bhT and bmh-T), premontane tropical (bh-PT and bmh-PT), and subtropical (bh-S, bmh-S and bp-S). It prefers Ortic Acrisols, Distric Cambisols and Fluvisols; soil textures of 34–78% sand, 8–48% silt, and 4–38% clay, and a pH of 4.4–6.2.
Cultivars and Chemotypes
There are no cultivars offered in agricultural trade; however, two chemotypes have been identified of Peruvian U. tomentosa: a tetracyclic oxindole alkaloid type (tetracyclica) and a pentacyclic oxindole alkaloid type (pentacyclica). It has been found that the pentacyclic alkaloid type is immunopotentiating; whereas, the tetraacyclic alkaloid type is immunosuppressing. In the traded product, these chemotypes have largely been ignored. The subject of which chemical profile is better, the stem vs. the root, is largely irrelevant due to the difficulty of trade in the root material of cat’s claw. The leaves have not been found useful commercially, however, there are groups in Lima who are researching this for possible commercial uses.
Guisella T. Brell of the Agrarian University of La Molina is involved in the micropropagation of cat’s claw (see selected experts). Transgenic cat’s claw root has been micropropagated in bioreactors, but this technology is still in the developmental stage, and is not yet commercially viable.
Generally, the propagation of the seed is difficult because viability rapidly declines after dehiscing, so cat’s claw is usually propagated asexually by cuttings. Eight-inch sections of the stem are cut for planting as cuttings. If the soil of the forest is moist enough, cuttings are said to be easy to reproduce by directly inserting them into the forest floor. If the conditions are right, the roots develop soon after transplant. However, others recommend reforesting cat’s claw through the use of natural regeneration. For natural regeneration, sufficient sunlight (canopy openings) is needed. In this case, the forest may be thinned to allow for easier natural regeneration, or cat’s claw may be allowed to grow in secondary forests where more sunlight gaps exist. Very few, if any, commercial plantations of cat’s claw exist. Most material is harvested in forests. Yield in managed forests depends on density, and densities that have been reported for U. tomentosa range from 2 to 8 individuals per hectare in natural forest, and 17 individuals per hectare in managed forest. Sustainable management of cat’s claw is becoming an issue in Peru, due to the popularity of this botanical medicine. INRENA requires management plans for the harvest and trade of cat’s claw, and more studies on the effect of harvest to the natural ecosystem are needed to assure sustainability.
Today, the root is not normally harvested because of the destructiveness of this method of harvest. The primary product in trade comes from the stem bark. Although there are different chemotypes found in the field, there are no known morphological differences to distinguish them. Generally, it is recommended that the vine is cut at 8 inches to a meter above the ground and left to regenerate. Vines are only harvested at 8 or more years old, otherwise the diameter of the vine is not sufficient for bark removal. As a regular practice, the cut vine is stripped of its bark in the field due to the weight of carrying out the whole vine, and the inner stem is disgarded. In Iquitos, this practice is currently opposite due to local commercial use of the inner stem for furniture making. The stem bark is not harvested commercially in Iquitos because it is too expensive to transport cat’s claw to Lima.
The Association for the Conservation of the Patrimony of Cutivireni (ACPC) recommends the following processing procedure for a quality product: the damaged (infected or punctured) inner bark is disgarded, and the drying is conducted on clean raised surfaces to avoid molding. It is generally dried in the sun or shade, and it is then best packaged in waterproof sacks for shipping.
Dolichandra unguis-cati, commonly known as cats claw creeper, funnel creeper, or cat’s claw trumpet, is a rapidly growing climbing vine belonging to the family Bignoniaceae.