A new species of fern for New Zealand, Asplenium lepidotum

Finding and naming new species is a core part of the job for Te Papa’s scientists.  More than 2500 animal and plant species have been named by museum staff since 1865.  A recent example is the fern Asplenium lepidotum, described by myself and Pat Brownsey.  This brings the number of indigenous ferns and lycophytes in New Zealand to 202.

Asplenium lepidotum is a new species, just recently described. Photo by Leon Perrie. © Te Papa.

Asplenium lepidotum is a new species, just recently described. Photo by Leon Perrie. © Te Papa.

How does Asplenium lepidotum differ?

Asplenium lepidotum looks similar to A. oblongifolium (shining spleenwort / huruhuruwhenua) and A. obtusatum (shore spleenwort).  They all have fronds that are once-divided.

The abundance of scales on the upper surface of young fronds is a distinguishing feature for Asplenium lepidotum. These scales appear as black dots. Photo by Leon Perrie. © Te Papa.

The abundance of scales on the upper surface of young fronds is a distinguishing feature for Asplenium lepidotum. These scales appear as black dots. Photo by Leon Perrie. © Te Papa.

The new species, Asplenium lepidotum, is most easily distinguished by the abundance of scales on the upper surface of young fronds.  Asplenium lepidotum further differs from A. oblongifolium in having broader scales on its frond axes, and from A. obtusatum in not being restricted to the coast.

The scientific paper that first described Asplenium lepidotum has a detailed comparison with its relatives, including images.

The scientific paper was published in New Zealand Journal of Botany.  Click here to access a pdf of the paper.  Otherwise, you can email me for the pdf.

Asplenium lepidotum has been recorded from the northwest of the South Island. The dots on the map correspond to specimens in the herbarium collections of Te Papa, Auckland Museum, and Landcare Research. The distribution of A. lepidotum overlaps with both A. oblongifolium and A. obtusatum. Map © Te Papa.

Asplenium lepidotum has been recorded from the northwest of the South Island. The dots on the map correspond to specimens in the herbarium collections of Te Papa, Auckland Museum, and Landcare Research. The distribution of A. lepidotum overlaps with both A. oblongifolium and A. obtusatum. Map © Te Papa.

Asplenium lepidotum is associated with base-rich substrates like limestone. It can be locally common, but, at a national level, it has been given a Naturally Uncommon conservation ranking. Photo by Leon Perrie. © Te Papa.

Asplenium lepidotum is associated with base-rich substrates like limestone. It can be locally common, but, at a national level, it has been given a Naturally Uncommon conservation ranking. Photo by Leon Perrie. © Te Papa.

If you are in a limestone area in the northwest South Island, there is a good chance that Asplenium lepidotum will be around.

An interesting feature of Asplenium lepidotum is that it can retain simple fronds to a much larger size than its New Zealand relatives. Photo by Lisa Bennett. CC BY-NC. From NatureWatchNZ.

An interesting feature of Asplenium lepidotum is that it can retain simple fronds to a much larger size than its New Zealand relatives. Photo by Lisa Bennett. CC BY-NC. From NatureWatchNZ.

How was Asplenium lepidotum found?

I first realised that there might be a new species about 14 years ago.  In the northwest South Island, I found plants that had scales on their axes as broad as those of Asplenium obtusatum, but these plants were growing well inland when A. obtusatum is restricted to the coast.  I subsequently noticed that these anomalous plants also had an abundance of scales on the upper surface of their young fronds.  Further research, including microscopic examination, gave us confidence that these plants were actually a distinct species, and this is what has recently been named A. lepidotum.

This discovery is a reminder that if you see something in nature that doesn’t fit expectations, it’s well worth a closer look.

How did it get its name?

Asplenium lepidotum was the first as-then unnamed species to feature in Te Papa’s exhibition You called me what?! This exhibition is celebrating 150 years of scientific discovery by Te Papa.

The You called me what?! exhibition.

We invited suggestions for the scientific name of this new species of fern.

You can read a summary of these suggestions on this Te Papa blog post.

Many people’s suggestions focused on the scales that occurred on the upper surface of the young fronds.  We thought this was a good idea, since this feature distinguished the new species from its similar relatives.

We were particularly inspired by Caitlin S and Meghan, who suggested lepidofolium and lepidium, respectively.

Ultimately, we chose lepidotum, which is from the Latin lepidotus, meaning covered with small scales.

Thank you very much to Caitlin S and Meghan, but also to the some 800 other people who also made suggestions.

If you want to have a go at giving a scientific name to a new species, check out the exhibition’s webpage: You called me what?!

Other blog posts about the You called me what?! exhibition.

For news about New Zealand’s ferns, see the Facebook group New Zealand ferns.

One Response

  1. Barbara Hammonds

    Great stuff Leon. Might see this species in January!

    Reply

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