Irish wildflowers

Rigid Hornwort, Ceratophyllum demersum

Rigid Hornwort
Ceratophyllum demersum
Family: Ceratophyllaceae

Flowering June-July. Submerged aquatic perennial. Native.

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

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

Rigid Hornwort, Ceratophyllum demersum       Rigid Hornwort, Ceratophyllum demersum

Above: Rigid Hornwort growing with Spiked Water-milfoil. The Gearagh, Co.Cork. August 2007

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