Asplenium australasicum.
The Bird’s Nest fern.
Pteridophyta > Class Polypodiopsida/Pteridopsida > Order Polypodiales > Family Aspleniaceae.
There are about 700 Asplenium species with about 30 native to Australia.
Asplenium australasicum is native to Queensland.
It usually grows on rocks or as an epiphyte on trees but will grow on well drained soil.
It has a stout, erect, unbranched rhizome with fronds radiating up and slightly outwards in all
directions forming a “nest ” in the centre.
This collects organic debris and water which nourish the plant.
The rhizome has thin grey, brown or purplish scales.
Fronds are fairly straight, glossy, pale to dark green and about 80 cm long and 21 cm wide.
They are a wide linear shape tapering to the tip, entire and with a wavy edge.
The basal stipe is only a few cms long.
The dark brown midrib is grooved or flat above and has a prominent ridge or keel underneath.
Many straight, fine parallel veins run at a slightly oblique angle from the midrib to the leaf margin
where they join the marginal vein.
Sporangia on the underside are in linear sori, 1 mm wide and up to 6 cm long, that run parallel to the
veins from the midrib towards but not up to the margin.
It can be distinguished from the similar A. nidus by the prominent ridge under the midrib.
J.F.
