Streblus asper, commonly known as Siamese rough bush or toothbrush tree, is a deciduous tree native to a variety of habitats including dry deciduous forests, open woodlands, and scrub areas across South and Southeast Asia, specifically in Indonesia, Cambodia, Thailand, India, Sri Lanka, Malaysia, and Vietnam. It typically grows to a height of 10-15 meters with a dense, rounded canopy. The leaves are distinctive with their rough, sandpapery texture, oval shape, and are dark green in color. The small, inconspicuous greenish-yellow flowers bloom in clusters, but the tree is not grown for its floral display.

Streblus asper is valued for its historical significance in traditional papermaking and its use in folk medicine. Its bark, which has been used for centuries to produce durable paper for Buddhist texts and official records, is also known for its antibacterial properties. The tree’s twigs are traditionally used as a natural toothbrush, helping to maintain oral health. In cultivation, it is often used in reforestation projects and can be planted as an ornamental in xeriscaping due to its drought tolerance. It requires full sun to part shade, well-drained soil, and can withstand poor soil conditions. While generally pest-resistant, it can occasionally suffer from leaf spot diseases.CC BY-SA 4.0