Rigid Hornwort - Ceratophyllum demersum

    Description

    Stem flexuous with rigid leaves in whorls of 3 to 8. Leaves dark green 1-2 forked divided into slender toothed segments. Flowers solitary with 8 or more linear petals, female flowers green, male flowers whitish. Fruit a small nut 4-5 mm with basal spines, otherwise smooth.

    Similar Species

    Ceratophyllum submersum

    Identification difficulty
    ID guidance

    Leaves forked 1 - 2 times

    Recording advice

    The County Recorder has asked for a specimen of this plant to be retained for verification

    Habitat

    Freshwater habitats, ponds, slow moving rivers and canals rooting in the muddy bottom.

    When to see it

    Flowers July to September.

    Life History

    Perennial.

    UK Status

    Fairly widespread in lowland areas of Britain.

    VC55 Status

    Occasional and local in Leicestershire and Rutland, but may be abundant where it occurs. In the 1979 Flora survey of Leicestershire it was found in 25 of the 617 tetrads.

    In the current checklist (Jeeves 2011) it is listed as native; now rarely recorded, but possibly overlooked

    Leicestershire & Rutland Map

    MAP KEY:

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

    UK Map