''Spirodela'' is a genus of

aquatic plant Aquatic plants, also referred to as hydrophytes, are vascular plants and Non-vascular plant, non-vascular plants that have adapted to live in aquatic ecosystem, aquatic environments (marine ecosystem, saltwater or freshwater ecosystem, freshwater ...

s, one of several genera containing plants commonly called

duckweed Lemnoideae is a subfamily of flowering aquatic plants, known as duckweeds, water lentils, or water lenses. They float on or just beneath the surface of still or slow-moving bodies of fresh water and wetlands. Also known as bayroot, they arose fr ...

. ''Spirodela'' species are members of the

Araceae The Araceae are a family of monocotyledonous flowering plants in which flowers are borne on a type of inflorescence called a spadix. The spadix is usually accompanied by, and sometimes partially enclosed in, a spathe (or leaf-like bract). Also ...

under the

APG II system The APG II system (Angiosperm Phylogeny Group II system) of plant classification is the second, now obsolete, version of a modern, mostly Molecular phylogenetics, molecular-based, list of systems of plant taxonomy, system of plant taxonomy that ...

. They were formerly members of the

Lemnaceae Lemnoideae is a subfamily of flowering aquatic plants, known as duckweeds, water lentils, or water lenses. They float on or just beneath the surface of still or slow-moving bodies of fresh water and wetlands. Also known as bayroot, they arose fr ...

Description

''Spirodela'' species are free-floating plants that have their

stem Stem or STEM most commonly refers to: * Plant stem, a structural axis of a vascular plant * Stem group * Science, technology, engineering, and mathematics Stem or STEM can also refer to: Language and writing * Word stem, part of a word respon ...

transformed into leaf-like structures called fronds; each plant is represented by a frond with roots, therefore they do not have leaves. Two to five plants may remain connected to each other. Plants are green, but may turn red due to the presence of

anthocyanin Anthocyanins (), also called anthocyans, are solubility, water-soluble vacuole, vacuolar pigments that, depending on their pH, may appear red, purple, blue, or black. In 1835, the German pharmacist Ludwig Clamor Marquart named a chemical compou ...

. Multiple

root In vascular plants, the roots are the plant organ, organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often bel ...

s (5 to 20, depending on the species) emerge from each frond. ''Spirodela'' is larger () than '' Lemna'' ( – , with one root per frond). Certain species of ''Spirodela'' overwinter as turions, dormant starchy shoots that lack air pockets, which sink to the bottom of the water. In spring, turions rise to the surface and germinate. ''Spirodela'' often forms floating mats with related species (e.g. '' Lemna'' and '' Wolffia)''. The genus is virtually cosmopolitan in distribution.Kew World Checklist of Selected Plant Families
/ref>Flora of North America
/ref>

Species

There are currently 2 recognized species in this genus: #''

Spirodela polyrhiza ''Spirodela polyrhiza'' ( ''S. polyrrhiza'') is a species of duckweed known by the common names common duckmeat, greater duckweed, great duckmeat, common duckweed, and duckmeat. It can be found nearly worldwide in many types of freshwater habitat ...

'' (L.) Schleid. - cosmopolitan #'' Spirodela intermedia'' W.Koch

References

External links

*Armstrong, W. (2005
Wayne Armstrong's treatment of the Lemnaceae
. *Cross, J.W. (2006)

The Duckweed Genome Project
Lemnoideae Araceae genera Aquatic plants {{Araceae-stub