Sphaeropteris lepifera

MP-0001 / 0024 — Cyatheaceae

Sphaeropteris lepifera (J.Sm. ex Hook.) R.M.Tryon
Hikage-hego (JP)

An arborescent fern with a trunk several metres tall and fronds that unfold from coiled croziers — among the largest tree ferns of the Japanese flora.

Distribution

Ryukyu Islands (Japan), Taiwan, southern China, the Philippines and New Guinea. In Japan it occurs only in the Ryukyu Archipelago.

Habitat

Humid evergreen broad-leaved forest, shaded ravines and stream valleys, typically under a closed canopy.

Morphology

An arborescent fern with an erect, unbranched trunk several metres tall. The crown carries very large, 2–3-pinnate fronds that unfold from coiled croziers (fiddleheads). The trunk is not true wood: it is formed of stem tissue wrapped in persistent leaf bases and a mantle of adventitious roots.

Botanical notes

A defining element of Yambaru forest structure. The root mantle of the trunk provides a substrate for epiphytes, mosses and small ferns. All tree ferns of the family Cyatheaceae are listed in CITES Appendix II.

References

Taxonomy and distribution follow Plants of the World Online (Kew), YList (Yonekura & Kajita) and regional floras; CITES Species+ for trade status. Descriptions are provisional and are revised as specimens are verified.