CERATOPHYLLUM DEMERSUM

Familly:- CERATOPHYLLACEAE

Common Name:- Rigid hornwort

Synonyms:- Ceratophyllum demersum var. commune, Dichotophyllum

demersum.

Meaning:- Ceratophyllum (Gr) Horn-leaf. (The stag's horn shape of the leaf).

Demersum (L) Underwater, submerged.

General description:- Very variable medium to tall bulbous perennial, smelling

strongly of onion or garlic when crushed, to 1.5 m.

Stems:-

1) 30-150 cm.

Leaves:-

1) 8-40 mm, rather stiff; upper leaves forked once or twice into linear, flattened,

spinose-denticulate segments 0·2-0·7 mm thick.

2) Lower similar or 3 or 4 times dichotomous.

Flowers:-

1) Male flowers 1-3 at a node.

2) Female flowers solitary.

3) Stamens, often more than 20.

4) Perianth, green in female flowers, whitish in male.

Fruit:-

1) Nut usually armed with 1 or more spines.

Key features:-

1) Most upper leaves forked once or twice, the segments conspicuously spinose-

denticulate.

2) Terminal spine of nut (1·5-)3·5-12 mm.

Habitat:- Shallow lakes, dams and canals with fresh or sometimes brackish,

nutrient rich water. 0-850 m

Distribution:- Scatterred throughout mainland Greece and Peloponnisos, Kerkira. -

Almost cosmopolitan in temperate areas. Rare on Crete known from only two

locations in the west.

Flowering time:- June-Sept, sometimes later.

Photos by:- Kind permission of Saxifraga - Free Nature Images