Annona muricata, universally known as soursop, graviola, or guanabana, is a tropical, broadleaf, evergreen tree in the family Annonaceae. Native to the tropical regions of the Americas and the Caribbean, it has been naturalized across tropical Africa, Southeast Asia, and the Pacific. The genus name Annona is derived from the Latin annona, meaning "yearly produce" or "harvest," while the species epithet muricata is Latin for "muricate" or "full of prickles," describing the distinct, soft-spined texture of the fruit’s thick skin. Historically, it has been a staple in indigenous Andean and Amazonian diets, where it was valued not only as a sweet-tart refreshing treat but as a sacred plant in various medicinal traditions.

The tree is relatively small, reaching heights of 5 to 10 meters, with a dense, spreading canopy of glossy, dark green, aromatic leaves. Its flowers are solitary and yellowish-green, featuring thick, fleshy petals. The fruit itself is a large, heart-shaped or oblong syncarp, often weighing up to several kilograms. Its exterior is a vibrant, bumpy green covered in soft, fibrous spines that are pliable rather than sharp. Beneath the inedible, leathery skin lies a brilliant white, fibrous, creamy pulp that contains numerous smooth, inedible black seeds. Annona muricata thrives in low-altitude, high-humidity tropical climates with well-draining soil and is commonly found in home gardens and small-scale tropical orchards.

The soursop is celebrated for its highly distinct, sweet-and-sour flavor profile, which is often described as a vibrant blend of strawberry, pineapple, and citrus with a creamy, custard-like texture. In tropical gastronomy, the pulp is primarily processed into juices, smoothies, and nectar drinks, as well as being folded into tropical ice creams, sorbets, and pastries. Because the pulp is fibrous and difficult to eat raw out of hand like an apple, it is almost always pressed through a sieve to extract the juice or incorporated into thickened dessert bases. In some parts of Southeast Asia, the young, firm green fruit is also cooked as a vegetable in savory stews or soups.

Nutritionally, soursop is a dense source of Vitamin C, B-complex vitamins (especially B1, B2, and B3), potassium, and dietary fiber. Its biochemical profile is among the most chemically unique in the botanical world, defined by the presence of a class of compounds called acetogenins. These compounds are found throughout the tree, but are most concentrated in the seeds and leaves, and are the subject of extensive scientific inquiry for their potent cytotoxic and anti-tumor potential. In traditional medicine across the Caribbean and South America, tea brewed from soursop leaves is widely used as a calming agent, a treatment for hypertension, and an aid for various parasitic infections.