Species of the Month - November 2016

Hartstongue Fern

Asplenium scolopendrium

Asplenium scolopendrium

As the year draws to a close, many flowering plants die down or lose their defining features, but most ferns keep in good shape throughout the winter, including the Hartstongue Fern which is fully evergreen.  It is very easily recognised as it is the only fern with completely undivided fronds.

Asplenium scolopendrium

The underside of the fronds bear linear sori containing the spores.  When young these are covered with a silvery indusium, which opens when the spores are ready for release.  There are actually two sori side-by-side along each vein, but they are so close together that as soon as the sporangia begin to expand, the pair of sori appear as a single brown line.

Asplenium scolopendrium

Hartstongue Fern in a shady gully in early March, with previous year's fronds still green and healthy.

  Asplenium scolopendrium

Fresh young fronds of Hartstongue Fern in early May, among limestone rocks with Hard Shield Fern.

Asplenium scolopendrium

Fully-expanded fronds in early August, still with a fresh green colour due to being in a sunny location.  The fern normally prefers shaded situations where it develops a leathery appearance.  It needs neutral to alkaline conditions and is absent from acidic rocks unless they are flushed with base-rich seepage, as often happens in the gorges of hill burns.  It is common on mortared walls but is unlikely to be found on dry stone walls unless they are of limestone.

Please send in
your Hartstongue Fern sightings using the form below, or email sightings@lnhg.org.uk with the details if you prefer.  If you are not sure of the identity of your fern, please send a photo to sightings@lnhg.org.uk, or put one on the LNHG Facebook page.

Date of sighting 
Grid reference 
Name of finder 
Your name (if different) 
Email (not needed if I already know it!) 
Any other details, e.g quantity, habitat    


By filling in this form you agree that the information contained in this form may be collated and disseminated manually or electronically for environmental decision-making, education, research and other public benefit uses in accordance with the LNHG data access policy.  Your email address will not form part of the record and will not be passed on to anyone.

Carl Farmer
LNHG Biological Records Manager

Sightings so far

Nov 13: Large stand in mixed broadleaved wood on east side of Seil Sound, James Fenton

Nov 29: Seen on several mortarted walls in Oban, Carl

Nov 30: Seen in Onich, Sallie


Note you can still send in records for past species of the month.  Here are the previous November species:

Nov 2014 - Golden Spindles
Nov 2013 - Whooper Swan
Nov 2012 - Feathered Thorn
Nov 2011 - Hazel Gloves

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This project is supported by Scottish Natural Heritage

All photos and other content copyright Carl Farmer except where stated.  The first 2 photos on this page are copyright Jan Hamilton.
Mouse over photos to see credits.