Asplenium is a well known genus of ferns, commonly known as “spleenworts”. There are about 700 species worldwide with around 30 native to Australia.
A.australasicum grows on trees (epiphytic) or rocks (lithophytic) and occasionally in the soil. It consists of large, elliptical shaped fronds arising from a central stem to form a deep, saucer shape. The spreading fronds can reach about 3 metres in diameter. The spores on the underside of the fronds occur in parallel rows. The species is easily confused with A.nidus which occurs on Cape York in north Queensland, and through New Guinea, tropical Southeast Asia and Africa and to Tahiti and Hawaii. Some old books still confuse the two species, however the true A.nidus is a tropical plant vulnerable to cold and must be grown in a glasshouse in temperate regions.
A.australasicum is a hardy and very popular fern in cultivation. It can be grown on trees or rocks or in the ground in soils containing appreciable organic matter. Although it likes plenty of moisture, it must have good drainage (similar to its situation in nature) as plants are vulnerable to rotting in poorly drained situations (consider a tub or hollow stump or tree to put it on). A.australasicum will tolerate at least moderate frost and prefers a situation in filtered sun. It will respond favourably to regular applications of general purpose fertilizers. Like most ferns, A.australasicum makes an excellent container plant for both outdoors and indoors.
Propagation is carried out from spores.
Photo: Fred Johnston