I had not added a new fern to my website for a long time until I came across Asplenium nitidum (family Aspleniaceae) recently. It was found in the same nature park that I spotted the Duckbill Lindernia (Bonnaya ruelloides) share in my note last week. Based on the pattern of the spore-bearing bodies and the overall shape of the fronds, it was not too difficult to identify the fern.

The fern was located on an Oil Palm (Elaeis guineensis) tree with 2 other ferns (Pyrrosia lanceolata and Goniophlebium percussum). Fortunately, it was position at my eye level which helped with my visual inspection of the fern. I had come by this location a few times but had not paid too much attention to the ferns on this Oil Palm tree. At a quick glance, this fern resembled the Rabbit’s Foot Fern (Davallia denticulata), which was a rather common fern in Singapore. There were several Oil Palm trees along the path, but Asplenium nitidum was only found on one of them. However, there should be more specimens hidden in the area since there were many Oil Palm trees among the dense vegetation.

The 2022 Singapore flora checklist indicated this fern’s status as Critically Endangered (“CR”) while the older 2009 Singapore flora checklist listed it as extinct. It meant that it was probably rediscovered after 2009. The clue was found in a 163-page Environmental Impact Study (EIS) report of the Turf City and Holland Plain published in 2022.

This fern was mentioned several times in the EIS report. In page 155, it confirmed that this fern was rediscovered in recent years. In page 167, it described a specimen found on a Rain Tree (Samanea saman) from the EIS study itself, mentioned that the last specimen available in Singapore was collected in 1907 and the rediscovery from a specimen collected in 2012 in Pulau Ubin. In page 170, it indicated a second specimen found on an Oil Palm tree from the EIS study. There was no reference provided in the report related to the Pulau Ubin specimen.

I tried to search for the publication related to the rediscovery of this fern at Pulau Ubin in 2012 but there was none. The closest I got was a Checklist of Vascular Plants of Pulau Ubin compiled and updated on 12 September 2014 from a link in NParks' website. Asplenium nitidum was listed in the checklist.

In the iNaturalist website viewed on 6 October 2024, there were 3 observations of this fern from Singapore; one of them observed in 2021 and the other two observed in 2022. Based on sightings reported so far, this fern appeared to be an epiphyte that grew on another plant. While there were already several sightings of this fern since 2009 in Singapore, I would still consider it as a very rare fern.