Members of the genus Drynaria are among the loveliest of the epiphytic ferns. They have the deeply incised fronds that are typical of ferns, an interesting biology, and are furthermore excellent for growing indoors.
The Drynaria fortunei is indigenous to the mountain forests of south-east Asia, where it is found at elevations of 500 to 1,200 m (1,600 to 4,000 ft). It generally grows in the forks of branches but is often found also on entirely smooth trunks. The appressed sterile leaves, which have a beautiful form (they resemble oak leaves but are naturally much larger), capture humus as well as moisture. The fertile leaves, up to 40 cm (16 in) long, are firm and somewhat leathery. In cultivation, where it is provided with much better conditions than in the wild (it is not as affected by temperature fluctuations and periods of drought), the leaves are often up to 75 cm (2’/2 ft) long.
Like asplenium, drynaria also tolerates more sunlight than most ferns. It benefits from occasional syringing, but the leaves will not dry up without it. However, if the compost (a light mixture of peat, sand, charcoal, crushed pine bark and beech leaves) dries out for a lengthy period then the fern will lose several fronds. Cultivation is the same as fornidus.
If you have ample room and decide to grow plants on a large epiphyte trunk you can use ferns of the genus Pseudodrynaria, generally represented in collections by the species P. coronans, which grows to a height of 140 cm (4 ft 8 in). Its thick, dark green leaves are truly magnificent. Pseudodrynaria also grows very well in the ground; for this purpose use a hollow log filled with a rather coarse epiphytic mixture.
The conditions for growing drynarias are achieved in glass plant-cases. However, they also thrive in conservatories, where they have ample fresh air, and excellent results may be obtained in the home.