The Dryopteridaceae is a large and diverse fern family with a near cosmopolitan distribution. Arachniodes (East Indian holly fern), Cyrtomium (net-veined holly fern), Didymochlaena (tree maidenhair fern), Dryopteris spp. (shield, buckler, wood or oak ferns), Nothoperanema (bristle fern), Polystichum (holly fern) and Rumohra (seven weeks fern) are some of the genera belonging to the family and which have representatives in the South African flora. Although only a few species occur in South Africa, these genera have approximately 570 species worldwide.

Description
Plants grow on the ground, on rocks, rarely in trees. They have a short scaly rhizome which may be erect or prostrate. Leaf stalks are also scaly and the leaves or fronds are pinnately divided; leaflets usually unequal-sided at the base; veins free or merging. Sori (clusters of spores)occur on the veins or at the vein tips. The sori may be covered by a kidney or umbrella shaped indusium (epidermal outgrowth covering the sori).

Scientific description

Distribution
The Dryopteridaceae is a large family with a near cosmopolitan distribution. The greatest number of species are found in southern, southeastern, and eastern Asia. In South Africa representatives occur from the Cape Peninsula eastwards along and south of the main mountain ranges to Eastern Cape, and from there northwards along and east of the Drakensberg to the Soutpansberg in the north, with outliers in the Kamiesberg. Within this range it occurs from near sea level to approximately 3000 m in the Drakensberg.

Name and history
Dryopteris is the type genus of the family Dryopteridaceae, and is derived from the Greek word drys meaning oak and the Latin word pteris meaning fern. Dryopteris species are also known as oak ferns, because they frequent oak forests in the northern hemispere.

Distribution and Ecology
Members of the wood fern family are mostly forest dwellers, but several species are restricted to grassland habitats. In forest habitats the plants generally occur in leaf litter on the forest floor, but often also on rocks or as low-level epiphytes. They occur in permanently or seasonally moist habitats. Some species are restricted to the summer rainfall region of South Africa, others occur in both the summer and winter rainfall regions. Grassland species generally occur in sinkholes along drainage lines or at boulder bases where they receive some protection. The subterranean rhizome ensures the survival of the plants from regular vegetation fires, which appear to have no damaging effect on them.

Economic and cultural value
Although several Dryopteris and Polystichum species are commonly cultivated as indoor and garden plants in the northern hemisphere, few species are locally available. Once established, I found them to be relatively hardy garden plants in light to deep shade. They do, however, require regular watering during the drier parts of the year. Rumohra adiantiformis, or the seven weeks fern, is a widely cultivated and hardy species. The fronds are highly sought after in the florist industry due to their longevity.
Various parts of the plant, but especially the rhizome of several Dryopteris species is used by the Zulu and Sesotho people for curing a range of ailments in both animals and humans.

In the Garden
During Victorian times sports of several Dryopteris and Polystichum species were highly sought after by gardeners. Many of these however, are no longer available. South African members of the Dryopteridaceae I find to be good garden subjects include Cyrtomium micropterum, Rumohra adiantiformis, Polystichum luctuosum, P. macleae, P. monticola, P. pungens, P. transvaalense and P. wilsonii. Didymochlaena truncatula, the tree maidenhair fern, is available but it requires deep shade and permanently moist conditions, preferably also a high humidity. Since most of these species are relatively large, they are not ideally suited for indoor cultivation, with the exception perhaps of Cyrtomium micropterum. These species are all evergreen and suitable for the shaded garden. Several species can tolerate direct sunlight for short periods of the day once well established, and when adequate moisture is provided. In the milder coastal regions no protection is required, but inland they may require protection during the cold winter months. Species with decumbent (lying close to the ground) rhizomes multiply readily by branching and are best propagated by division. Species with suberect or erect rhizomes will require propagation by spores as offshoots are not readily produced.

Reference

• Roux, J.P. 2001. Conspectus of southern African Pteridophyta. Southern African Botanical Diversity Network (SABONET) Report No. 13.
  
  

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  J.P. Roux Compton Herbarium February 2004