PLANT OF THE WEEK

Dr. T. Ombrello - UCC Biology Department

STAGHORN FERNS

Common names:        

Staghorn fern, Elk’s horn fern, Antelope ear  

Scientific name:    Platycerium species

Explanation of scientific name:

Platycerium - the Greek word for broad-horn

The 17 species of Staghorn ferns represent one of the most unusual groups of ferns.  The leaves of many of the members of the Staghorn genus (Platycerium) are antler-like in appearance rather than like a typical fern’s foliage.  Once seen, it becomes apparent why the common names and the scientific name for this group are most appropriate.

Staghorns have just about a worldwide natural distribution.  For example, Platycerium bifurcatum comes from Eastern Australia, New Guinea, and New Caledonia;  Platycerium andinum is native to Peru and Bolivia; Platycerium alcicorne is found in Madagascar; and Platycerium grande originates from Australia, Singapore, and the Philippines.  While mostly tropical, a few species can tolerate cold weather.  Platycerium bifurcatum, the most common species imported into this country, can tolerate temperatures as low as 15^oF.

Besides their unusual shape, Staghorns occupy an uncommon habitat.  They do not grow rooted into the ground, they are instead epiphytes -  they “grow upon others”.  Commonly found on trunks of trees or in the crotches of limbs, Staghorns use these plants for support, but are not parasites and do not draw any nutrition from their hosts.  For nutrition and moisture, the Staghorns rely on leaves falling from above to decay into humus, and frequent rainfall.  They are perfectly adapted to their habitat since they thrive on a loose, light, humus soil, that is well drained and never remains water saturated for any significant length of time.

Like all other ferns, the Staghorns produce no flowers, fruits, or seeds.  They reproduce themselves primarily by spores, which are single-celled reproductive units that are produced on the undersides of leaves.  These spores are released and carried by the wind.  Some fall on a suitable location, perhaps hundreds of feet above the ground in a tree, and begin the next generation of Staghorns that will ultimately grow into mature plants.  Staghorns also can reproduce by means of “pups”.  Mature plants produce small but intact plantlets (pups) that can detach from the parent plant, and fall to take root somewhere below, often on the same tree.

Unlike other ferns, most Staghorns have 2 kinds of leaves or fronds.  One of these is the sterile leaf, which is shield or dish shaped.  It is called sterile because it does not produce spores.  Each sterile leaf, as it grows, clasps the support on which it is found.  Initially green, they turn brown and become parchment-like with age.  Besides holding the plant in place, the spaces between the layers of sterile leaves accumulate water and dead decaying vegetation, supplying moisture and humus to the plant.

The other leaf type is the fertile leaf.  It is erect or spreading and mostly antler-forked.  It remains green at maturity, to carry on photosynthesis to provide nutrition for the plant.  It is called fertile because it produces spores, found mostly at or towards the ends of the antlers.  The white, dust-like material that is visible on the leaves is actually hair projecting from the leaf surface.  These star-shaped (stellate) hairs are thought to inhibit moisture loss from the leaf surface.

Staghorns make hardy and long-lived houseplants, as long as one recognizes their natural requirements and duplicates them as best as possible.  They thrive if attached to a plaque along with some humus.  They should be watered frequently, letting them dry slightly between waterings.  They enjoy very bright light but not full sun.  While individual staghorns have been known to reach several hundred pounds in weight, the indoor gardener should not worry about this happening under household conditions.