Ceratopteris cornuta (P. Beauv.) Le Prieur

Global description

Ceratopteris cornuta is an annual aquatic fern with pinnate ​​fronds forming a tuft that can reach 1 m in height. It can be rooted with fronds immersed or spreading on the water surface, or free-floating. The frond (limb) is simple deeply lobed, bipinnate in its upper part (cut twice in lobes) and reduced to the rachis in its lower part which evokes a long petiole. The fertile fronds have revolting filiform linear lobes covering the sporangia. This species is very polymorphous according to the conditions of the environment. The sporangia are on the underside, emitting yellow spores.

General habit

Depending on the depth of the water, Ceratopteris cornuta develops as an upright tuft rooted in the mud or as a free-floating plant more or less spreading.

Underground system

Vertical rhizome 15 mm in diameter.

Stem

Pseudo stem (stipe) glabrous, succulent and fragile when it is fresh, from 4 to 18 cm long.

Frond

Fronds (leaves) are very polymorphic. The fertile fronds, often numerous are generally triangular or obovate 7 to 27 cm long and 5 to 18 cm wide, pinnate or bipennatifid, rarely tripennatifides at the lobes of the base. The terminal lobes are triangular to lanceolate, with abruptly acute tops. The upper face and the lower face are glabrous, the margin is sub-entire. The fertile fronds are generally lanceolate to oval in shape. They are longer and much more finely dissected than sterile fronds. They are 11 to 69 cm long and 4.5 to 28 cm wide. They are 3 to 4-pennatifides, the ultimate lobes being closely linear, attenuated in tip at the top. Both sides are glabrous and the margin is inrolled.

Sporangium

The reproductive organs are sporangia, arranged in 1 to 3 rows along the veins, on the underside of the fertile fronds. They produce yellow spores.

https://www.gbif.org/species/8330991