Ripogonum scandens, commonly known as kareao or the New Zealand supplejack, is a woody climbing vine (liana) endemic to the native forests of New Zealand, belonging to the monogeneric family Ripogonaceae. The Māori name kareao reflects its deep significance in indigenous culture, where it was historically prized not only for its versatile materials but also as a traditional source of nourishment. The genus name Ripogonum derives from Greek roots meaning "flexible vine," perfectly describing its signature growth habit, while the species epithet scandens is Latin for "climbing." The plant has long been a defining architectural feature of New Zealand’s temperate rainforests, twisting through the canopy and forming dense, tangled thickets that can make forest travel notoriously difficult.

The vine features tough, cylindrical, woody stems that can grow up to 15 meters or more in length and reach several centimeters in diameter, wrapped in smooth, dark brown or grey bark. As it climbs toward the light, it produces strong, wiry tendrils and leathery, glossy green leaves arranged in opposite pairs or whorls along the stem. It produces small, greenish-white or pale yellow flowers grouped in axillary racemes, which are later followed by clusters of round, fleshy berries. These berries transition from green to a striking, glossy red or black color upon maturity, each containing a few hard seeds. Ripogonum scandens thrives in damp, shaded lowland and montane forests, showing a strong preference for fertile, well-draining soils with high organic matter.

As a traditional food and utilitarian source, the supplejack vine played a vital role in Māori life and early European settlement. While the berries are generally not consumed, the starchy, thick rhizomes (underground stems and roots) and the tender young shoots—often likened to wild asparagus—were utilized for sustenance. The growing tips can be cooked and eaten as a vegetable, while the starchy underground roots were traditionally pounded, soaked, and roasted to extract fermentable carbohydrates during times of scarcity. Beyond its culinary uses, the exceptionally flexible and durable stems were invaluable for crafting woven items, including baskets, eel traps (hīnaki), frames, and temporary shelters, earning it a reputation as the "cordage of the forest."

From a medicinal and chemical standpoint, traditional Māori herbal medicine (Rongoā) made extensive use of the plant. Decoctions prepared from the boiled roots or stems were traditionally used as a blood-purifying tonic, to soothe digestive discomfort, and to treat skin conditions such as boils and eczema due to its mild astringent and cleansing properties. Modern botanical and phytochemical analyses of Ripogonum scandens have identified various bioactive secondary metabolites, including saponins, flavonoids, and tannins, which contribute to its traditional reputation as an anti-inflammatory and cleansing agent.