A medium-sized, brown-green liverwort with obliquely inserted, broadly trilobed leaves in an open, upland habitat is likely to be O. floerkei. However, microscopic examination is often needed to separate this species from several others. Its most important feature is a complete lack of any leaf gemmae and this separates it from all similar-looking species except non-gemmiferous forms of O. atlanticus and Barbilophozia hatcheri, which normally have red gemmae.
Under the microscope, close attention should be paid to features such as cilia, found close to where the leaves meet the stem and on underleaves (pictured) and cell sizes.
O. floerkei is a calcifuge species and thus avoids the calcareous habitats favoured by Tritomaria quinquedentata, which in any case is green, lacks underleaves and has asymmetrically lobed leaves.Read the Field Guide account