Linum monogynum, the rauhuia or New Zealand linen flax, is a species of flowering plant in the family Linaceae, which is endemic to New Zealand. It is a low-growing short-lived perennial or woody subshrub, growing up to 16 in (41 cm) tall. Its spear-shaped, leathery-gray to green leaves are 0.2–1 inches (5–25 mm) long. Its pretty white flowers are up to 1 in (2.5 cm) in diameter, and have five overlapping petals. It is monoecious, having both male and female organs on one plant (hence the Latin specific epithet monogynum, literally "single wife").