Irish wildflowers BSBI map

Rigid Hornwort, Ceratophyllum demersum, Cornlach
Photographs: The Gearagh, Co. Cork

Rigid Hornwort
Ceratophyllum demersum
Cornlach
Family: Ceratophyllaceae

Flowering June-July. Submerged aquatic perennial. Native.

Minute monoecious flowers are stalkless and auxillary but the smooth or slightly warty fruit is rarely produced. Branched stems with numerous whorls of 6-8 rigid, dark-green leaves. Leaves are 1-2 times forked, the segments fine-toothed. Stems to 1m.

Rare, very local distribution in Ireland in still or slow-moving lakes, ponds and canals. Identified by Paul Green

Similar: Spiked Water-milfoil, Myriophyllum spicatum

Rigid Hornwort, Ceratophyllum demersum, Cornlach

Rigid Hornwort, Ceratophyllum demersum, Cornlach
Rigid Hornwort, Ceratophyllum demersum, Cornlach

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