Teratophyllum rotundifoliatum

Teratophyllum rotundifoliatum is a climbing fern from the family Dryopteridaceae (male fern family). It is not , as sometimes claimed, a member of the Hymenophyllaceae (skin fern family).

T. rotundifoliatum is native to Borneo, primarily in the Malaysian part (Sabah and Sarawak). It can also be found in the south of the Malaysian peninsula and occasionally on Sumatra.

It always grows in very dark and permanently damp habitats, climbing over damp, moss-covered stones, rotting tree trunks, and the buttress roots of mighty rainforest trees. This fern is a true shade specialist and exhibits some extreme adaptations to its specific habitat. Apart from the veins, the fronds are extremely thin (90 to 120 µm) and consist of only two layers of epidermal cells. The actual leaf tissue (mesophyll) is completely absent. The chloroplasts, which are usually only found in the mesophyll, are located in the epidermis of this fern. Like many other shade plants , Teratophyllum rotundifoliatum also displays a blue iridescence in low light.

This fern has dimorphic fronds. As a young plant, it forms so-called bathyphylls. These are initially very simple and rounded, clinging closely to their support. As they grow larger (and longer), they differentiate further and split into once- or twice-pinnate fronds. They reach a size of about 2 to 6 cm. Our *T. rotundifoliatum * is at this stage. Finally, after many years and several meters of growth, the so-called acrophylls develop, which then also bear the spores. These are much, much larger than the bathyphylls and completely different in shape. They do not lie close to the support but stand out widely and can reach up to 40 cm in length! This mature stage is extremely rare. There is no photograph of an acrophyll of *T. rotundifoliatum* , and only a few herbarium specimens contain acrophylls. This form will probably never be reached in terrarium cultivation.

T. rotundifoliatum grows very slowly. In our experience, under good conditions it takes about two years to grow 50 cm. Keeping it in a tropical terrarium is not difficult, but requires a great deal of patience.



You will receive a strong, well-rooted plant approximately 5 to 8 cm long in a 9 cm orchid pot. These are plants with fully developed bathyphylls, not tiny baby plants!