Drynaria rigidula – Basket or Oakleaf Fern.
Division Pteridophyta > Order Polypodiales > Family Polypodiaceae > Tribe Drynarieae.
Drynaria are distinguished from other ferns by having differently shaped nest and fertile fronds
which are partly or completely lobed.
(The Elk and Stag horns have 2 types of fronds but their fertile ones fork repeatedly.)
There are around 15 Drynaria species with 4 found in Australia including one natural hybrid.
Drynaria rigidula.
A large creeping or clumping epiphytic fern growing on trees or, in Australia, on rocks.
It is found in Queensland and is the only species with pinnate fronds.
The large rhizome is covered in long red-brown scales up to 12 mm long and fringed with fine hairs.
Nest and fertile/foliage fronds grow alternately along the rhizome.
The erect, sterile nest fronds are from 10 cm up to 1 m long and have no stalk.
They are ovate or narrow, with rounded, shallow or deep lobes.
They collect organic debris and protect the rhizome and remain even when dry and brown.
The pale green fertile fronds can be erect or arching and up to 2m long.
The brown, slightly winged stalks can be up to 40 cm long.
The fronds are pinnately divided with up to 40 pairs of leaflets.
The narrow leathery leaflets are up to 25 cm long and on short stalks with narrow wings.
Leaflet bases are wedge-shaped, the tips pointed and the edges have small, irregular teeth.
There is a prominent central midrib.
All fronds are partly or wholly covered with scales and star shaped hairs.
The sori are arranged in a row on either side of the midrib of fertile fronds.
They are round, up to 2 mm wide, sunken and produce a small bump on the upper surface.
J.F.
