SPECIES DESCRIPTION
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 02-07 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 (15-)35-12 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