Restio quadratus, commonly known as Square Stem Restio, is an evergreen perennial grass-like plant native to the fynbos biome of the Western Cape in South Africa. It typically grows to a height and width of 3-6 feet (0.9-1.8 meters), featuring upright, square-shaped stems that give it its common name. The plant is adapted to a Mediterranean climate with wet winters and dry summers, thriving in sandy and well-drained soils. Square Stem Restio does not bear flowers in the traditional sense but has brown, insignificant flower heads that are wind-pollinated, appearing in spring.

Square Stem Restio is valued for its architectural form and textural contrast in gardens. It is used in ornamental plantings, mass plantings for ground cover, and as an accent in water-wise gardens due to its drought tolerance once established. It requires full sun to maintain its form and prefers soils with medium to fast drainage. While it can tolerate some shade, its stems may become leggy. Regular watering is necessary during its first growing season to establish a deep root system; thereafter, it can survive with less frequent watering. It is generally pest and disease-free but can be susceptible to root rot if overwatered or planted in poorly drained soils.CC BY-SA 4.0