Identification notes
To have a good chance of finding Colura, you need to understand the kind of micro-habitat it prefers and then find that habitat. As a strongly oceanic liverwort, it needs places where the air is constantly humid, and where there is protection from desiccating winds, hot sun and extreme cold.
In many lowland areas, this means the bark of trees and shrubs growing by, or above water and next to evergreen conifers or tall rhododendrons. Favoured micro-habitats include sprawling Salix cinerea (grey willow) by streams in the lee of conifer plantations, or on the conifers themselves. In high rainfall areas of the far west, and hilly districts elsewhere where there is often fog, Colura can also be found on scattered willows and gorse and even boulders in the open.
Colura is a very poor competitor so home your search in on young bark that has few other epiphytes – perhaps a little Metzgeria violacea, small Lejeuneaceae species or Orthotrichum pulchellum. You will rarely find it in places where the bark has much bryophyte cover.
It often grows conveniently at head height and then the trick is to scan the bark looking for tiny bright green lumps perhaps only a millimetre or two wide – where you get it, there are often numerous such plants scattered about. They become all but invisible when the bark is wet, so it’s worth carrying a cloth to dab down suitable branches!
If you are very lucky, you may even come across tufts of Colura with pretty little star-shaped perianths (nice images below), or even capsules.
Read the Field Guide account