The Piai Raya (Acrostichum aureum) is a large clump-forming mangrove fern commonly found at the inland side of mangroves and freshwater marshes.
The fern can grow as tall as 4m, sometimes forming dense stands at sunny areas.
The leaf tips are generally blunt, sometimes with a small point.
The other mangrove fern, Piai Lasu (Acrostichum speciosum), is much smaller (up to 1.5m tall) and the leaves have elongated pointed tips.
Like other ferns, they reproduce from spores, and large sporangia cover the undersides of fertile fronds.
The fern's young leaves are eaten by the locals in some areas, and dried leaves are used for thatching. The rhizomes are used to treat wounds.
- Chong, K. Y., H. T. W. Tan & R. T. Corlett, 2009. A Checklist of the Total Vascular Plant Flora of Singapore: Native, Naturalised and Cultivated Species. Raffles Museum of Biodiversity Research, National University of Singapore. Singapore. 273 pp.
- Giesen, W., S. Wulffraat, M. Zieren & L. Scholten. 2006. Mangrove guidebook for Southeast Asia. RAP Publication 2006/07. FAO Regional Office for Asia and the Pacific & Wetlands International. Bangkok. 769 pp.
- Ng, P. K. L., and N. Sivasothi. 1999. A guide to the mangroves of Singapore 1 : the ecosystem & plant diversity. Singapore Science Centre. Singapore. 168 pp.