Golden Leather Fern (Acrostichum aureum): Coastal Wetland Fern

Overview

Golden leather fern (Acrostichum aureum), also known as mangrove fern or coastal leather fern, is a massive, salt-tolerant fern of tropical and subtropical coastlines worldwide. Its leathery, pinnate fronds can reach 3–4 m in height, making it one of the largest ferns in cultivation.

Botanical Description

Fronds are erect, arching, simply pinnate, 2–4 m long and 30–60 cm wide. Pinnae are leathery, oblong, 10–20 cm long, with entire margins. The upper pinnae are fertile, their undersides completely covered in golden-brown sporangia (hence "golden" leather fern). The rhizome is massive, woody, and creeping, forming large colonies in suitable habitat.

Taxonomy

Family:	Pteridaceae
Genus:	Acrostichum (ak-ro-STISH-um)
Species:	aureum (AW-re-um)

Habitat and Distribution

Native to mangrove swamps, tidal marshes, and brackish wetlands in tropical regions worldwide (Americas, Africa, Asia, Pacific). One of the few ferns that thrives in full sun and saline conditions. Often grows alongside mangroves (Rhizophora, Avicennia).

Cultivation

• Light: Full sun to part shade.
• Soil: Wet, brackish to saline; tolerates freshwater if kept very moist.
• Hardiness: USDA zones 10–11; frost-tender.

Uses and Notes

Primarily grown in botanical gardens and large conservatories. In tropical landscapes, used for wetland restoration and coastal stabilization. Young fiddleheads are edible (cooked) in some cultures. The rhizome has traditional medicinal uses. Requires vast space and constant moisture—not a typical garden plant.