Morinda citrifolia, commonly known as noni, Indian mulberry, or great morinda, is a tropical evergreen shrub or small tree in the coffee family (Rubiaceae). Native to Southeast Asia and Australasia, it has been spread extensively by humans throughout the Pacific Islands, India, and the Caribbean. The genus name Morinda is derived from the Latin morus ("mulberry") and indica ("of India"), reflecting the fruit's physical resemblance to a mulberry. The species epithet citrifolia refers to its leaves, which botanically resemble those of the citrus genus. Historically, noni is a "canoe plant," having been intentionally transported by Polynesian voyagers as a foundational source of food, medicine, and dye across the vast expanse of the Pacific.

The plant is characterized by its large, dark green, glossy, and deeply veined leaves, which provide a stark backdrop for its white, tubular flowers that emerge from globose flower heads. Its fruit is a syncarp, meaning it develops from the fusion of many individual flowers into a single, fleshy, yellowish-green mass. As the fruit matures, it develops a characteristic lumpy, potato-like appearance and emits a pungent, "cheesy" aroma due to the presence of short-chain fatty acids like octanoic and hexanoic acid. Morinda citrifolia is remarkably hardy, thriving in a wide range of environments from volcanic terrain and coastal limestone to saline soils, often acting as a pioneer species in disturbed areas.

As a food source, noni is traditionally viewed as a "famine food" rather than a daily staple, often consumed only during times of scarcity. In parts of Southeast Asia and the Pacific, the fruit is eaten raw with salt, or the skin is peeled and the flesh is cooked into curries and soups. In modern times, the fruit is most famously processed into noni juice, a fermented, highly concentrated extract that has gained global attention as a functional "superfood" tonic. The young leaves are also considered highly nutritious and are commonly boiled or steamed in various Pacific and Asian cuisines, valued for their bitterness and high protein content.

Nutritionally, noni is a complex reservoir of secondary metabolites. It is rich in Vitamin C, potassium, and various phytochemicals. The fruit is chemically distinguished by its high concentration of iridoids, particularly aucubin, asperuloside, and scopoletin, which are linked to the plant's traditional therapeutic reputation. The fermentation process of the juice further increases the complexity of its bioactive profile, yielding a variety of unique phenolic compounds. In traditional medicine, almost every part of the plant is used: the roots were used to create a yellow dye, the bark a red dye, and the fruit and leaves as an analgesic, anti-inflammatory, and immune-modulating poultice or tonic.

Major ingredients derived from this food source include fermented noni juice, dehydrated noni fruit powder, and boiled noni leaf infusions. Significant bioactive compounds associated with the source include scopoletin, damnacanthal, aucubin, asperuloside, and a diverse range of anthraquinones (such as morindone) which are largely responsible for its medicinal reputation and the coloring properties of the roots and bark.