Cashews do not grow on common apples. These popular nuts originate from Anacardium occidentale, a distinct tropical tree that produces a unique fruit structure. This plant yields both the cashew nut and a fleshy, colorful part commonly referred to as the “cashew apple.” The nut’s development in relation to this fruit is unusual.
Understanding the Cashew Apple
The cashew apple is botanically classified as an accessory fruit, also termed a pseudocarp or false fruit. It develops from the flower stem (pedicel) and receptacle, rather than from the plant’s ovary. It ripens into a pear-shaped or oblong structure, displaying yellow or red hues. The cashew apple is about 5 to 11 centimeters long and possesses a juicy, fibrous pulp.
Although edible and used locally for juices, jams, or fermented beverages, the cashew apple is delicate and does not transport well, limiting its global distribution. The actual cashew nut, botanically a true fruit or drupe, grows externally at the bottom of this fleshy, pseudo-fruit. This distinctive arrangement makes the cashew plant unique.
The Journey from Plant to Nut
The cashew tree (Anacardium occidentale) is a tropical evergreen species native to northeastern Brazil. It thrives in warm climates and can grow up to 14 meters tall, though smaller cultivars are preferred for commercial cultivation due to earlier maturity and higher yields. The tree produces small, yellowish-pink flowers in clusters.
Following pollination, the kidney-shaped cashew nut develops first. Subsequently, the pedicel (flower stalk) attached to the nut expands and swells to form the fleshy cashew apple. This process results in the mature nut hanging below the larger, colorful cashew apple. Harvesting occurs once the cashew apples and their attached nuts ripen and fall to the ground, signaling the nuts’ maturity.
The cashew nut has a double shell containing a caustic, oily resin known as cashew nut shell liquid (CNSL). This liquid, rich in anacardic acid, is a skin irritant, similar to compounds found in poison ivy. Due to this toxic substance, raw cashews require careful handling and processing, including roasting, before they become safe for consumption. This process neutralizes the irritants, making the kernel edible.
The Origin of the Misconception
The misunderstanding that cashews grow “on apples” stems from the naming convention of the “cashew apple.” The term “apple” is used due to the fruit’s visual resemblance in shape and color to traditional apples. Its pear-like form and red or yellow skin contribute to this association.
Despite this superficial similarity, the cashew apple is botanically unrelated to true apples (Malus domestica). The confusion is compounded by the fleshy cashew apple, with the nut dangling from its end. This unique growth habit can mislead those unfamiliar with the plant’s biology. The term highlights a visual likeness rather than a botanical connection.