by João Felipe Toni
The project aimed to enable young people to discover the nature and culture in the Amazon, and in particular to become more familiar with its flora as well as its uses by locals. Through artistic activities, botanical lessons and an excursion to the Tropical Greenhouses of the Botanic Garden of Zürich, the students learnt about the tropical rainforests and the ecology of palms of the genus Euterpe, also known as açaí. The flower biology, ecological importance and use of these palms by humans as food and medicine (especially by indigenous communities) were discussed during the activities. At the end, a buffet of açaí berry recipes was prepared and the students presented their inquiry on the topic.
Euterpe is a genus of native tropical palm trees found in the Amazon and a few Caribbean islands. There are three species producing edible fruit found widely dispersed through the Amazon: Euterpe edulis, Euterpe precatoria, and Euterpe oleracea.
The “Jussara palm”, or Euterpe edulis Mart. can be found both in the Amazon and in the Atlantic rainforest of the Brazilian coast. Their palm hearts are used as food. The fruits of Euterpe oleracea Mart. and Euterpe precatoria Mart. are found exclusively in the Amazon and are also used as food. Here is the name of the palm açaizeiro, the fruit açaí. In Europe, the fruit is marketed under the name açaí berry.
The Brazilian species Euterpe were first described in 1824 by Carl Friedrich Philipp von Martius. During three years, from 1817 to 1820, Martius and Spix travelled over thousands of miles through Brazil, from Rio de Janeiro via Salvador to the Amazon region, braving heavy rains, heat, thirst and disease. With their animal and plant studies and their ethnological observations of multiethnic society, they left an extraordinary testimony of Brazil that still inspires today to engage with the country’s history and identity.
For natives that live among the thousands of islands found in eastern Amazonas, in Pará and Amapá States, the acaí fruit is a major source of nutrition. Yet what makes this fruit remarkable is not just its nutritional profile and antioxidant properties, but how little pulp is found within the fruit due to the size of the seed in the fruit relative to the pulp. Hence, it takes a lot of fruit to provide enough pulp to feed the millions of people who rely on it as a major source of nutrition in the Amazon rain forest (Schauss 2009).
But how do the açaí berries originate on the palm tree?
With this question we draw the student’s attention to some of the fundamental processes responsible for the flower morphology and the ecology of the açaí palm.
These palms produce one to four bisexual inflorescences per flowering period. Inflorescences have staminate and pistillate flowers in triads. Both male and female flowers emit an almond oil-like scent and produce nectar in septal nectaries which attracts the most constant visitors and potential pollinators: beetles of the families Curculionidae, Chrysomelidae, Staphylinidae, and bees of the family Halictidae. Once the flowers are pollinated and fertilisation occurs, the fruit development lasts four months and ripe fruits are swallowed by toucans who thus disperse the seeds (Kuchmeister et al. 1997).
Through this example it was possible to introduce to the students the notion of interrelatedness in nature and between nature and ourselves. The problem of deforestation, loss of biodiversity and of social erosion in tropical countries became now a question of global responsibility and global thinking.
Goulding, M & Smith, N. (2007): Palms. Sentinels for Amazon Conservation. Missouri Botanical Garden Press.
Küschmeister, H. et al. (1997): Flowering, pollination, nectar standing crop, and nectaries of Euterpe precatoria ( Arecaceae ), an Amazonian rain forest palm. Plant Systematics and Evolution 206(1):71-97
Schauss, A. G. (2009): Açaí (Euterpe oleracea Mart.): A Macro and Nutrient Rich Palm Fruit from the Amazon Rain Forest with Demonstrated Bioactivities In Vitro and In Vivo. In: Ronald Ross Watson and Victor R. Preedy, editors, Bioactive Foods in Promoting Health. Oxford: Academic Press.