The Spleenwort – Asplenium

Asplenium is one of the most popular houseplants in the family of Aspleniaceae which consists of seven hundred evergreen ferns widely distributed around the world. It has a very diverse growth form as the genus includes terrestrial and epiphytic species and the species that grow on the rocks. The variations among the species made the distinct features that differentiate from a species to another species. Some make dense turfs of fronds or rosettes. Others creep across the surface with the thick and scaly rhizomes. Most species have feathery pinnate or bipinnate fronds but the leaves are large and undivided in some species. The fronds of many species develop small plantlets along the ribs. The spore-bodies are typically arranged in a capsule known as sporangium that is parallel or radiating lines on the undersides of the fronds.

Many Asplenium ferns are epiphyte, which means they are easy to maintain. Although the difficulty level varies greatly from species to species in terms of the optimal growing environment. Most species prefer woodland conditions with cool, moist, humus-rich soil and dappled shade that mimic a jungle or forest condition. A few species need sunnier locations that are also categorized as species that able to tolerate dry conditions. Spores mainly propagate the propagation of this genus. The capsule releases mature spores when it is stimulated by moisture, especially on a rainy day. It is also found that the division of established clumps, removal of rooted pieces of rhizomes, as well as the growth of the frond-borne plantlets on the frond are found effective as alternatives for propagation.

There are some popular species that commonly available in the nursery. Asplenium trichomanes, known as maidenhair spleenwort, is an evergreen or semi-evergreen species with dark green pinnate fronds that is only about 3 – 8 inches long. It is commonly found on limestone outcrops. Mauritius spleenwort, which is scientifically known as Asplenium daucifolium that originated from Madagascar and Mauritius. It has arching fronds, which are dark green that up to three feet long that divided into a very narrow segment, thus giving a delicate lazy effect. Similarly, Asplenium bulbiferum (hen and chicken fern or mother fern) originated from Australia, and New Zealand is a widely cultivated species. It grows easily in the pot or hanging baskets. It has a tuft or arching, deep green, finely divided fronds up to 1 m long and 30 cm wide that typically looks like a fern.

Among all, bird’s nest ferns are the striking group due to their appearance and low maintenance as indoor plants. Out of 700 species, two species share the same common name, which is Asplenium australasicum and Asplenium nidus. Asplenium australasicum is found in Australia and the South Pacific. This species has leathery and undivided fronds that somewhat v-shaped in cross-section. The frond can grow up to five feet long by eight inches wide forming a dramatic large “nest” or funnel. It is frost tender and requires warm and humid conditions to thrive. Therefore, it is found to grow on tree trunks or rocks in the wild. Moreover, Asplenium nidus is a pantropical, epiphytic fern that colonizes trees, rock faces, and boulders in humid, tropical rainforests that have the origins of tropical Asia, tropical Africa, and the Pacific. The front is characterized by glossy green, thin, tongue-like fronds with wavy margins and prominent or almost black midribs. They arise from a densely hairy crown in a radial fashion that somewhat resembling a bird’s nest. Similar to Asplenium australasicum, it needs warmth and ample humidity.

Bird’s nest fern is a gorgeous true fern, although it does not look like a typical fern with thin leaves. Generally, their leaves’ edges are smooth. However, in some cultivars, rippled or undulating edges are observed and variegation leaves with pale yellow color are present. Brown spots, which are known as sori, are found on the undersides of the leaves that contain the spores for dispersal during rainy days or humid conditions. The leaves that sporulate will slowly turn brown and eventually die. As the old and dead leaves curl up at the base of the plant, it is advisable to cur them off to maintain the tidiness and fresh looking of the plant and to avoid the growth of fungus on dead leaves. A curled shiny new green leaf that is called fiddlehead will slowly uncurl and will replace old brown leaves.

Since it is an epiphytic species that often anchor itself onto a solid object, there is no need to have any potting medium for it. Alternatively, sphagnum mosses can be used to keep this plant gets enough moisture all the time. It prefers moderately bright filtered light and can tolerate quite a bit of shade in low light conditions, which made it a perfect houseplant apart from soilless cultivation. It is highly sensitive to chemical sprays such as insecticides, fungicides, and leaf-polishing agents. Foliage will show the burning sign and turns brown as a result of chemical sprays. Therefore, minimal conditions of liquid fertilizer can be applied. It survives greatly without the need of having any fertilizers. The fern requires a lot of water; therefore, it is important to make sure the fern roots or the sphagnum moss are always moist to keep this plant hydrated.

It can be planted in a pot by placing a saucer or tray of water and make sure there is not directly sit on the water. It could be separated by pebbles or hang it as kokedama. Kokedama using this plant needs no special soil or media other than its fern roots. Sphagnum moss can be used to increase the spherical volume of the kokedama. If there are any small trees in the house, it is possible to “mount” this plant onto the tree by tying up with a nylon fishing line that is transparent in color. Misting can be done daily using a spray bottle or a handheld mister. It is one of the great indoor plants that contains an ancient element that gives a feeling of the Jurassic element in the house.

Further reading:

Aguraiuja, R. (2005). Hawaiian endemic fern lineage Diellia (Aspleniaceae): distribution, population structure and ecology.