Microsorum thailandicum (oil fern)

• Origin: Thailand
  
• Care: Easy / Medium / Advanced
• Suitable as a houseplant?: Yes / Limited / No
• Suitable locations: Terrarium
  
• Special features: Young plants do not yet show the blue coloration.

[porto_content_box border_top_color="#1e764d" border_radius="2" border_top_width="2" align="left"]

[expand Title=" Details about the plant "]



Microsorum thailandicum is a small fern from the Chumphon province in southern Thailand. It has an apparently relatively small distribution area and has so far only been collected from one mountain in the region. It grows epiphytically or lithophytically in crevices of limestone rocks.

*M. thailandicum* grows with a compact, climbing rhizome. The leaves are linear (long and thin, with a uniform width) and reach approximately 20 to 30 cm in length and 2 to 3 cm in width. They are noticeably thickened and stiff, almost succulent, with a sunken midrib. The upper surface of the leaves is a deep metallic blue. Unlike the blue iridescence of begonias, which can only be observed in the dark when a flashlight or strobe light shines on the leaves from a specific angle, the blue color in *M. thailandicum* is always visible. Even wetting the leaves with water does not make the color disappear; on the contrary, it tends to intensify it. The nanostructures responsible for the coloration are different from those found in begonias. Further details can be found in this blog post .

The coloration likely serves a different function than the iridescence of most other blue plants. It is thought that in M. thailandicum, it acts as sun protection rather than a method of capturing extra light. While this fern does grow in the shady undergrowth of a rainforest, it is not as dense as one might expect. Individual patches of sunlight frequently reach the forest floor, and these are approximately 1,000 to 10,000 times brighter than the ambient light that otherwise reaches the ground. The reflective blue coloration of M. thailandicum is thought to protect against precisely this sudden, intense light.



Microsorum thailandicum is also often sold as Microsorum steerei , but this is a different species.

Here you can see the differences between the two species (enter the names in the search field; a direct link isn't possible). As you can see, the two don't look particularly similar. So why there's this confusion about the names isn't entirely clear to me.



[/expand]

[/porto_content_box]