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NZ Plants

Tmesipteris elongata - fork fern

Family: Psilotaceae

Tmesipteris elongata lacks roots and true leaves. It is occassionaly terrestrial but usually an epiphyte on tree fern trunks. It has a creeping stem (rhizome) that lacks roots, absorbing water instead with filamentous rhizoids. A pendulous and undivided aerial stem is formed that lacks true leaves, functioning instead with scale leaves. Scale leaves are spirally arranged, dull green, narrow, tapering and flexible. Round-ended sporangia are fused in pairs and lie on the upper surface at the base of forked fertile leaves.
Found throughout New Zealand .

Vegetative characteristics

Fertile scale leaf and sporangia

Plant form: pendulous branched or unbranched stem, up to 150 cm long

Distrilbution, appearance: throughout the stem or mostly at the lower portion; forked, shorter than sterile leaves

Scale leaf arrangement: spiral or opposite

Sporangium location: upper surface of fertile scale leaf

Scale leaf shape: oblong to narrow, tapering to a short spine-like tip

Sporangium position: at base of  fertile scale leaf

Scale leaf size: up to 40 mm  

Sporangia distribution: in a fused pair (synangium) of equal size,  2-6 mm long

Scale leaf surface: dull light-green, slightly leathery

Sporangium shape: with round ends,

Leaflets: 0  Sorus covering: 0