Most mangroves along the Seberang Perai coast can be told apart by their roots:
- Api-api (Avicennia): pencil-like breathing roots poke up from the mud around the tree. These are the pioneers of the seaward edge.
- Bakau (Rhizophora): arching stilt roots prop the trunk up above the water.
- Berus and tumu (Bruguiera): knee-shaped roots loop in and out of the mud, on firmer ground behind the seaward edge.
- Berembang (Sonneratia): thick, cone-shaped breathing roots, along brackish riverbanks.
- Nipah (Nypa fruticans): the mangrove palm, with long fronds rising straight from the mud of tidal creeks.
Api-api putih (Avicennia alba)
The white mangrove is a pioneer of the seaward side of the forest and is often one of the first trees to colonise newly formed mudflats, where it copes with harsh tidal conditions. Look for a dark trunk and narrow leaves that are pale underneath.
Api-api (Avicennia marina)
The most common mangrove in Penang. It grows right on the coast front, in the lower intertidal zone, where it tolerates stronger waves and saltier water than most mangroves. The surest sign is its reddish-brown bark, which flakes off in papery scales.
Berus (Bruguiera cylindrica)
Also called bakau putih or the small-fruited mangrove. It grows on higher, firmer ground behind the api-api, and its knee-shaped roots make it easy to recognise.
Tumu merah (Bruguiera gymnorhiza)
The large-leaved orange mangrove grows in the back mangrove. Its solitary, nodding flowers have a thick, woody calyx that is reddish-pink to bright red, especially in the sun. That red calyx is the easiest way to tell it from other Bruguiera, which usually have greenish or yellowish calyces.
The species notes and photos above are by the Malaysian Nature Society (MNS) Penang. Photos of the other species were taken at the PIFWA Mangrove Education Centre in Sungai Acheh.
