Division Lycopodiophyta > Class Isoetopsida > Order Selaginellales > Family Selaginellaceae.
Selaginellaceae are not true ferns but are spike mosses or fern allies.
There are about 700 species with 10 -14 native or naturalised in Australia, most in Queensland.
Selaginella willdenowii is known as the iridescent or peacock fern because of its metallic bluish-green leaves.
Terrestrial ferns, initially erect its branches can be metres long either lying on the ground or scrambling up any support.
The branches fork repeatedly and they lie in one plane.
The main stem is smooth, pale brown and shiny with small leaves widely spaced on it.
These leaves are about 3 mm long, with a round tip and heart-shaped base.
They lie flat on the stem all pointing along it.
There are 2 types of sterile leaves on the branches – the paired lateral ones and the small median one.
i.) Lateral leaves are in 2 ranks.
Leaves in each rank overlap one another.
They are about 4 mm long at the base of the branch but smaller towards its tip.
They are ovate or sickle-shaped with a squared base, a blunt tip and a smooth edge.
The base of the lower side of each leaf has a small lobe or ligule with a wavy
edge that overlaps the stem.
ii.) Median leaves are flattened against the stem and overlap.
They are a similar shape to the laterals with the basal ones about 2.5 mm long but
smaller towards the top of the branch.
Fertile leaves or sporophylls are on a terminal spike, up to 12 mm long on the tips of the sterile branches.
These leaves are widely ovate, about 1.5 mm long, have a pointed tip and are keeled (ridged).
Each leaf has a male or female sporangium on the upper surface.