Ivy-leaved Duckweed

 

Scientific Name: Lemna trisulca L. 

Family: Lemnaceae

 

MORPHOLOGY

 

Habit and size: A perennial aquatic floating herb, measuring 2-4 cm with a filamentous root for each leaf.

 

Stem: Stem reduced to a bud at the leaf margin.

 

Leaves: Lanceolate-spatulate leaves (1-3 x 10-12 mm), with a capillary rootlet at the base of which two divergent leaves are inserted.

 

Flowers: Solitary flower (interpretable as a reduced spadix). Monoecious, with male flowers reduced to 2 stamens, female flowers to one carpel. Rarely blooms from March to October.

Fruits and seeds: The fruit is a nutlet.

 

DISTRIBUTION AND HABITAT

 

Present throughout Italy except in Valle d’Aosta, Marche, and Calabria, in lakes, rivers, and watercourses, from sea level to 1,000 m.

 

INTERESTING FACTS

 

A plant that forms extensive populations (even pure) on eutrophic running waters. In temperate zones, it overwinters through resting buds that sink in late autumn and rise in spring. It is a plant that oxygenates and purifies water.

 

Photo: Not subject to licensing by iNaturalist, Saxifraga, and Jan van der Straaten.