Species of the Month - February 2019

 Teddy-bear Moss

Rhytidiadelphus triquetrus

Rhytidiadelphus triquetrus

Most mosses don't have English names, apart from an incredibly uninspired list of artificial ones created a few years back.  "Teddy-bear Moss" is an alternative name given by bryologist Gordon Rothero to Rhytidiadelphus triquetrus, so I am using it here.  It is very apt with the moss's floppy head and fat stiff arms.

Rhytidiadelphus triquetrus   Rhytidiadelphus triquetrus

This is a large upright moss with red stems and numerous short branches often curved slightly downwards.  The leaves spread out at an angle from the branches whether wet or dry.  The leaves are not all curved in the same direction as in R loreus, its very common relative, but spread out evenly all round the branch.  R triquetrus has larger leaves than any of the species you're likely to confuse it with.  Its stem leaves are usually about 5 mm long and the leaves on a well-grown branch will be 3 mm or more long.  If your moss looks like R triquetrus and has leaves of the right length then you have it!

Rhytidiadelphus triquetrus
Stem leaves
  Rhytidiadelphus triquetrus
Branch leaves

The stem leaves are very broad just above the base and then taper evenly to a long narrow tip.  The leaf surface is pleated.  The branch leaves are similar but not so broad.

This moss is most frequent in the north and west of Britain.  It suffered severely from pollution in the more industrial areas, but is now returning to them.  In our area it is common in fairly open woodland or on semi-shaded banks.  It can grow on acid, neutral or calcareous soil.  It can also occur on open hillsides where it may be less upright and harder to recognise.

Rhytidiadelphus triquetrus   Rhytidiadelphus triquetrus

A rather stubby one from Inverawe on the left, and Jan Hamilton's beautiful photo from LNHG's 2015 North Shian field trip on the right.

Rhytidiadelphus triquetrus

Frozen teddy-bears from our trip down to the woods in Feb 2010 at Glen Gallain

For more info on Rhytidiadelphus triquetrus see the British Bryological Society species page

Please send in your Teddy-bear Moss 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 moss, 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

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

Feb 2018 - Elf's Ears
Feb 2017 - Black-eyed Susan (lichen)
Feb 2016 - Dotted Border
Feb 2015 - Tree Lungwort
Feb 2014 - Pale Brindled Beauty
Feb 2013 - Coral Lungwort
Feb 2012 - Barren Strawberry

Last month's page
Next month's page
Current month's page

Complete list of Species of the Month

All photos and other content copyright Carl Farmer except where stated.  The 7th photo is Jan Hamilton.  Mouse over photos to see credits.