Close-up views:

For quite a while, I have been pondering whether this fern and Giant Sword Fern (Nephrolepis biserrata) was actually referring to the same species. It seems to be so as indicated in the Flora of Singapore checklist 2009 where Nephrolepis biserrata is mentioned as a synonym of Nephrolepis auriculata.

The Plant List website has listed Nephrolepis biserrata and Nephrolepis auriculata as 2 different species while the Ferns of Thailand, Laos and Cambodia website listed only Nephrolepis biserrata and nothing on Nephrolepis auriculata

After sighting the above cultivated sword fern that looked like Nephrolepis biserrata, I might have made some sense out of this confusing situation. The distinguishing feature between the 2 ferns appeared to be the way that the pinna (leaflets) are lined up along the rachis (main vein) of the frond (leaf) when view from the underside. In Nephrolepis biserrata, the pinna cover up the rachis partially (right picture below) while the pinna of Nephrolepis auriculata do not cover up the rachis (left picture below).

The other differentiating feature is likely to be its sori (spore-containing bodies) arrangement. As I have yet to find a Nephrolepis auriculata with sori, I will not be able to make any comparison. But from the pictures seen in the Internet, there appears to be some differences.