Aeschynomene aspera, commonly known as the sola or pith plant, is a perennial herb native to freshwater wetlands, marshes, and the edges of water bodies in South and Southeast Asia. It is often found in seasonally flooded areas, adapting well to the monsoon climates of the region. This species typically grows to a height of 1-2 meters and has a distinctive appearance with its open, airy branching and small yellow flowers that bloom in the warmer months. The flowers, while not particularly showy, are of interest to pollinators in its native habitat.

The pith plant is valued for its low-density wood, which is among the lightest in the world and is traditionally used to make sola topis (pith helmets) and various crafts, showcasing its cultural significance. In cultivation, it can be grown as an ornamental in water gardens or naturalized in wetland areas. It requires full sun to part shade, consistent moisture, and can tolerate a range of soil types as long as they are wet. While it is considered a minor weed in rice paddies, it is not generally aggressive in managed garden settings. Its cultivation outside of native areas should be monitored to prevent potential invasiveness.CC BY-SA 4.0