Hemisphaeric Liverwort - Reboulia hemisphaerica

    Description

    This medium-sized thallose liverwort has dichotomously branching, flat, leathery thalli up to 8 mm wide, often forming loose mats. Plants are weakly aromatic, and the upper surface of the thallus is pale or glaucous green, contrasting with the red or purplish margins. The surface is smooth, with a faint network of lines and inconspicuous air pores. The male receptacles form sessile, often purplish cushions. Female receptacles are borne on short, terminal stalks and are green and hemispherical with 4 to 7 spreading or deflexed lobes. Air pores are quite conspicuous on the receptacles.

    Similar Species

    Preissia quadrata differs in its darker green thalli that taste peppery, more conspicuous and elevated air pores, and both male and female receptacles borne on stalks. Its female receptacles consistently have 4 ridges, each terminating in a short lobe.

    Identification difficulty
    Recording advice

    Unless identified by a recognised expert, a photo is required and the specimen should be examined with a microscope. In the comments box, state the key or ID method used and describe the size and identifying characters.

    Habitat

    It often grows on calcareous soil on or under boulders, in crevices of cliffs, rocks and walls, in limestone pavement and on earthy banks. 

    When to see it

    It prefers some shade, and grows mainly in winter, when conditions are moist and vascular plants are less competitive.

    UK Status

    Fairly widespread in Britain.

    VC55 Status

    Status in Leicestershire and Rutland not known.

    Leicestershire & Rutland Map

    MAP KEY:

    Yellow squares = NBN records (all known data)
    Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

    UK Map