Photo 11-09-2016, 12 14 22

The tiny liverwort Colura calyptrifolia (photographed with an iPhone and a x20 handlens!)

Colura calyptrifolia (or to give it its appropriately creepy-sounding common name, the Fingered Cowlwort), is one of our most fascinating UK liverworts. Absolutely tiny (the leaves are about a millimetre long and whole plants often only 2-3 mm), it is heavily modified from the basic leafy-liverwort body plan, the leaves formed into inflated sacs like miniscule balloons with pointed “beaks” at one end. These tiny sacs have even tinier trapdoor-like flaps that only open inwards, allowing them to capture ciliate protozoa and other microscopic creatures (conclusively observed in another species of the same genus). It’s not yet certain if the liverwort gains nutrients from “swallowing” these animals, although this might be a reasonable hypothesis given the similarity of the mechanism to that found in much larger carnivorous plants such as bladderworts.

Photo 11-09-2016, 12 14 20

The leaves of Colura are modified into tiny ballon-like sacs that trap small animals

This colony was spotted yesterday in Anglezarke, Lancashire following the British Bryological Society (BBS) AGM in Manchester. Populations of Colura have undergone a spectacular expansion over the last 10 or 20 years, particularly in conifer plantations where they occur as tiny epiphytes. Previously the plant was rather rare, occurring mostly on rock in humid gullies and restricted to the wetter areas of the far west. This sighting was on the trunk of a willow at the edge of a reservoir.

Something else that has changed rapidly over the last 10 or 20 years is the ease with which small things can be photographed and shared. These pictures were taken simply by pointing the camera of an iPhone through a x20 handlens (the latter much cheaper than an iPhone and even more useful!),  and if we had wished could have been made available online instantaneously. As poorly-known biodiversity is increasingly threatened globally, should we be making better use of cheap imaging and real-time networking of expertise to facilitate species discovery and monitoring?



Barthlott, W., Fischer, E., Frahm, J.-P. & Seine, R. (2000). First Experimental Evidence for Zoophagy in the Hepatic Colura. Plant Biology 2(1):93-97. 

Blockeel, T L, Bosanquet, S D S, Hill, M O and Preston, C D (2014). Atlas of British & Irish Bryophytes. Pisces Publications, Newbury.