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

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Leicestershire & Rutland Map

MAP KEY:

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

UK Map