Dipteryx odorata (commonly known as "cumaru" or "kumaru") is a species of flowering tree in the pea family, Fabaceae. That tree is native to Central America and northern South America. [1] Its seeds are known as tonka beans. They are black and wrinkled and have a smooth, brown interior. Their fragrance is reminiscent of vanilla, almonds, cinnamon, and cloves.
The word "tonka" is taken from the Galibi (Carib) tongue spoken by natives of French Guiana; it also appears in Tupi, another language of the same region, as the name of the tree. The old genus name, Coumarouna, was formed from another Tupi name for tree, kumarú.
Biology of the tree
editThe tree itself grows up to 25-30 meters, with a trunk of up to one meter in diameter. [2] The tree bark is smooth and gray whereas the wood is red [3]. The leaves alternate and are pinnate with 3-6 leaflets. The leaves are leathery, glossy and dark green. The color of the flowers is rose. Each developed fruit contains one seed. D. odorata is pollinated by insects. The worst pests are the bats because they eat the pulpy flesh of the fruit. There are a few fungi known, which may cause problems: Anthostomella abdita, Diatrype ruficarnis, Macrophoma calvuligera and Myiocopron cubense. [2]
The seeds
editThe tonka seed contains coumarin, a chemical isolate from this plant, which also gave the name to it. The seeds contain about 1 to 3 % of coumarin, rarely it can achieve 10 %. [2] Coumarin is responsible for the pleasant odor of the seeds and is used in the perfume industry. Coumarin is bitter to the taste, however, and, in large infused doses, it may cause hemorrhage and liver damage as well as it can paralyze the heart. [2] It is therefore controlled as a food additive by many governments. Like a number of other plants, the tonka bean plant probably produces coumarin as a defense chemical. Radio-carbon dating of D. odorata stumps left by a large logging operation near Manaus by Niro Higuchi, Jeffrey Chambers and Joshua Schimel, showed that it was one of around 100 species which definitely live to over 1,000 years. Until their research, it had been assumed unlikely that any Amazonian tree could live to old age due to the conditions of the rain forest.[4]
Agricultural aspects
editCumaru belongs to the emergent plants. It is a light-demanding calcifuge tree and grows on poor, well drained soils. The best growth is reached on fertile soils rich in humus. In the native region there is a mean annual temperature of 25 °C and approximately 2000 mm rainfall per year with a dry season from June to November. [5] In general it has a very low plant density. But depending on the agricultural use the density and also the age of the trees diversifies. In seed production systems, the plant density is higher and the trees are older than in timber production systems. [5] The tree is flowering from March to May, and the fruits ripen until June to July. [2] So the fresh fruits are picked up in June and July, fallen pods are harvested from January to March [2] or sometimes earlier. [3] The hard outer shell is removed and the beans are spread out for 2-3 days to dry and after that they can be sold. [2] The major producer is Venezuela, followed by Brazil and Colombia. The most important importing country are the United States. There it is used especially in the tobacco industry. [2]
Social aspects
editThis species is well known locally and generates an important income for rural families particularly as a buffer in times of hardship. [3] It is used for timber and non-timber products and so it is crucial that the use of this resource occurs in a sustainable way. The yield of beans per tree is about 1-3.5 kg per year but Cumaru trees produce a large volume of seeds every four years. This fact results in a gender dynamic. During years of low seed productivity, household income is controlled by the women. They buy food and basic resources such as clothing and school supplies to sustain the family. In years of heavy production, men control the income. During those seasons they invest the earnings in higher cost goods including motorcycles and chainsaws. [3]
References
edit- ^ Dae Sik Jang, Eun Jung Park, Michael E. Hawthorne, Jose Schunke Vigo, James G. Graham, Fernando Cabieses, Bernard D. Santarsiero, Andrew D. Mesecar, Harry H. S. Fong, Rajendra G. Mehta, John M. Pezzuto, and A. Douglas Kinghorn, 2003. Potential Cancer Chemopreventive Constituents of the Seeds of Dipteryx odorata (Tonka Bean). Journal of Natural Products, Volume 66, Number 5
- ^ a b c d e f g h CRC handbook of alternative cash crops, page 238-239
- ^ a b c d Patricia Shanley, Murilo da Serra Silva, Tadeu Melo, Rachel Carmenta, Robert Nasi, 2012. From conflict of use to multiple use: Forest management innovations by small holders in Amazonian logging frontiers. Forest Ecology and Management 268:70-80
- ^ Anna Lewington and Edward Parker, Ancient Trees: Trees that Live for a Thousand Years (Collins & Brown: London, 1999), p. 64
- ^ a b Cristina Herrero-Jáuregui, Plinio Sist, Miguel A. Casado, 2012. Population structure of two low-density neotropical tree species under different management systems. Forest Ecology and Management 208:31-39