Plant 212

Platycerium species (Polypodiaceae)


Staghorn fern

Fronds of these epiphytic ferns form extraordinary structures that would not look out of place hung over a mantelpiece in a hunting lodge. Platyceriums have two frond types, both of which contribute to their likeness to elk or stag horns and give rise to their common names. The sterile basal fronds of adult plants form large, overlapping kidney-shaped plates which support the plant and protect the roots. In contrast, and according to species, the fertile fronds either arch elegantly upwards like antlers; or cascade downwards from the basal plates.

Platyceriums usually grow as epiphytes, establishing on the trunks and branches of supporting plants. In some species, the modified basal shield fronds form bowl-like structures that help to capture rainwater and leaf litter. Platyceriums can form imposing colonies, with individual plants more than one metre across and with fronds more than one metre in length. Platycerium wandae from New Guinea is truly enormous, reaching in excess of two metres at maturity.

There is only one South American species, Platycerium andinum; the rest of the genus (c. 17 species) is distributed from Africa through Southeast Asia and New Guinea to Australia. Platycerium madagascariense is from the cloud forests of eastern Madagascar, whilst the semi-arid region in the west of the island is home to the endemic Platycerium quadridichotomum.

The diversity of habitats in which these ferns can be found means there are species well suited to cultivation. Some such as Platycerium bifurcatum are very cold hardy, even tolerating light frosts, whilst other species need a minimum of 15 degrees Celsius. Several species of Platycerium are grown in the glasshouses at Oxford Botanic Garden and many make excellent houseplants suitable for a kitchen, bathroom or conservatory. In cultivation platyceriums can be grown in pots or baskets and are often mounted on pieces of hardwood or attached to slabs of rough, cork oak bark for support. This bark is harvested from oak trees approximately 25 years old, and is a by-product of the cork industry.

Platycerium propagation is quickly achieved by division, removing 'pups' (sprouts) from the stout rhizomes of vigorous plants in spring or early summer. Another fascinating method, which is easy and rewarding, is by sowing spores. Observing the spores as they germinate, it is possible to see both stages of the fern lifecycle. Spore germinate to form tiny gametophytes which produce sperm and eggs that fuse to form the mature sporophyte.

Further reading

Christenhusz MJM and Chase MW 2014. Trends and concepts in fern classification. Annals of Botany 113: 571-594.

Hoshizaki BJ and Moran RC 2006. Fern Grower's Manual. Timber Press.

Kreier H-P and Schneider H 2006. Phylogeny and biogeography of the staghorn fern genus Playtcerium (Polypodiaceae, Polypoiidae). American Journal of Botany 93: 217-225.

Kate Pritchard