Cashews are widely enjoyed in dishes and snacks globally, popular for their distinctive flavor and creamy texture. Their origins and unique plant characteristics often spark curiosity, as the cashew’s journey from its native environment to widespread use involves an interesting history and surprising botanical features.
The Cashew’s Native Home
The cashew tree (Anacardium occidentale) is indigenous to tropical South America, with its origins specifically traced to northeastern Brazil. Tupi-Indian tribes were among the first to utilize both the nut and cashew apple in their diet. This tropical evergreen tree thrives in Brazil’s restinga and cerrado biomes, characterized by arid thickets and sandy or stony soils.
Wild cashew trees can exceed 10 meters (33 feet) in height, though cultivated varieties are dwarfed for efficient harvesting. The plant is well-adapted to hot, lowland areas that experience a distinct dry season. The world’s largest cashew tree in Pirangi do Norte, Brazil, exemplifies this expansive growth, covering 7,300 to 8,400 square meters. Its extensive canopy results from branches rooting upon touching the ground, creating a sprawling, multi-stemmed structure.
Global Journey of the Cashew
The cashew’s global dissemination began in the 16th century with Portuguese explorers and traders. During their voyages to Brazil, these explorers encountered the cashew tree and recognized its potential. They introduced the plant to other tropical regions, notably India and parts of Africa, around 1560-1565.
Initially, the cashew tree was not primarily cultivated for its nuts in these new territories. In India, it was planted for purposes like preventing soil erosion and afforestation, particularly along coastal areas. Over time, as the tree adapted to warm, coastal climates, the cashew nut’s value as a food source and commodity became apparent. This historical spread laid the groundwork for India, Africa, and Southeast Asian countries as major cashew producers.
Unique Features of the Cashew Plant
The cashew plant possesses unique biological characteristics that distinguish it from other “nuts.” What is commonly known as the cashew “nut” is the true seed of the cashew tree. This kidney-shaped seed grows at the end of a larger, fleshy structure known as the “cashew apple.” The cashew apple is a pseudofruit, meaning it develops from the pedicel and receptacle of the cashew flower rather than solely from the flower’s ovary.
The cashew apple itself is an edible, pear-shaped or oval structure that ripens to a yellow or red color, typically measuring 5–11 cm (2–4.25 inches) long. It is juicy and can be consumed fresh or used in beverages, though it is highly perishable and bruises easily, making transport challenging. The cashew nut’s shell contains a caustic phenolic resin, including urushiol. This is the same irritant found in poison ivy and poison oak. This toxic oil necessitates careful processing, such as roasting or steaming, to remove the irritant before safe consumption.