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NZ Plants

Hymenophyllum revolutum

Filmy Fern Family: Hymenophyllaceae

Hymenophyllum revolutum is small terrestrial or epiphytic filmy fern with long-creeping stems (rhizomes) forming extensive, interwoven patches of very thin, light green, hairless fronds with toothed margins. Sori are on short stalks at the base of the leaflets.
An endemic species found in damp lowland to mountane forest throughout the North Island and the western parts of the South Island.

Vegetative characteristics

Fertile frond and sporangia

Plant form: creeping rhizome with fronds up to 11 cm

Frond appearance: similar to sterile frond

Frond stalk, midrib: stalk (stipe) wiry, hairless; midrib (rachis) narrowly winged in upper part

Sporangium location: near rachis

Frond shape: elliptic to oval

Sporangium position: on short stalks at base of leaflets

Frond blade: 2-3-pinnate (divided 2-3 times into leaflets or pinnae)

Sporangia distribution: in groups (sori)

Frond surface: filmy, translucent

Sorus shape: rounded

Leaflets: linear-oblong or forked; toothed margin

Sorus covering: indusium flaps deeply toothed