All Topics  
Lemnaceae

 
Lemnaceae

 
   Email Print
   Bookmark   Link
 

 

Lemnaceae
 
 
  Topics Lemnaceae Topic Home

Lemnaceae is a family of flowering plants, also known as the duckweed family, as it contains the duckweeds or water lentils. Since duckweeds are now considered to be a branch of the arum or aroid family (Araceae
Araceae

Araceae is 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 hood....
), the name 'Lemnaceae' is rapidly falling out of use among taxonomists, who treat it as a subfamily called Lemnoideae.

These plants are very simple, lacking an obvious stem or leaves.






Discussion
Ask a question about 'Lemnaceae'
Start a new discussion about 'Lemnaceae'
Answer questions from other users
Full Discussion Forum



Encyclopedia


Lemnaceae is a family of flowering plants, also known as the duckweed family, as it contains the duckweeds or water lentils. Since duckweeds are now considered to be a branch of the arum or aroid family (Araceae
Araceae

Araceae is 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 hood....
), the name 'Lemnaceae' is rapidly falling out of use among taxonomists, who treat it as a subfamily called Lemnoideae.

These plants are very simple, lacking an obvious stem or leaves. They consist of a small 'thalloid' or plate-like structure that floats on or just under the water surface, with or without simple rootlets. The plants have become highly reduced from their relatives in Araceae
Araceae

Araceae is 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 hood....
. Reproduction is mostly by budding, but occasionally a flower
Flower

A flower, sometimes known as a bloom or blossom, is the reproduction structure found in flowering plants . The biological function of a flower is to mediate the union of male sperm with female ovum in order to produce seeds....
 consisting of two stamens and a pistil is produced (some view the 'flower' as a pseudanthium
Pseudanthium

A pseudanthium or flower head is a special type of inflorescence, in which several flowers are grouped together to form a flower-like structure....
, or reduced inflorescence
Inflorescence

An inflorescence is a group or cluster of flowers arranged on a Plant stem that is composed of a main branch or a complicated arrangement of branches....
, with three unisexual flowers, derived from the spadix
Spadix

In botany, a spadix is a type of raceme: an inflorescence with small flowers crowded on a thickened, fleshy axis. The term is applied to certain monocotyledons, especially members of the Family Araceae called arums or aroids....
 in Araceae
Araceae

Araceae is 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 hood....
). The fruit
Fruit

The term fruit has different meanings dependent on context, and the term is not synonymous in food preparation and biology. In botany, which is the scientific study of plants, fruits are the ripened Ovary of flowering plants....
 is a utricle, a sac containing air and a seed designed to float. The flower of the Wolffia currently holds the record for being the smallest flower in world; measuring in at a size of 0.3 mm long.

Duckweed is an important food source for waterfowl
Waterfowl

Waterfowl are certain wildfowl of the order Anseriformes, especially members of the family Anatidae, which includes ducks, goose, and swans.They are strong swimmers with medium to large bodies....
 and are eaten by humans in some parts of Southeast Asia
Southeast Asia

Southeast Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India and north of Australia....
 (as khai-nam). Some duckweeds are used in freshwater aquarium
Aquarium

An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. fishkeeping use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants....
s and ponds where they may spread rapidly and, in a large pond, may be difficult to eradicate once established. The plants can provide nitrate
Nitrate

In inorganic chemistry, a nitrate is a salt of nitric acid with an ion composed of one nitrogen and three oxygen atoms . In organic chemistry the esters of nitric acid and various alcohols are called nitrates....
 removal (if cropped) and cover for fry
Spawn (biology)

Spawning is the production or depositing of large quantities of egg s in water. The process is done by marine animals such as amphibians and fish....
. The plants are used as shelter by pond water species, such as bullfrog
Bullfrog

The American Bullfrog is an aquatic frog, a member of the family Ranidae, or "true frogs", native to much of North America. This is a frog of larger, permanent water bodies, swamps, ponds, lakes, where it is usually found along the water's edge ....
s and bluegill
Bluegill

The Bluegill is a species of freshwaterfish sometimes referred to as bream, brim, or copper nose. It is a member of the sunfish family of order Perciformes....
s. The duckweeds are important in the process of bioremediation
Bioremediation

Bioremediation can be defined as any process that uses microorganisms, fungi, phytoremediation or their enzymes to return the natural environment altered by contaminants to its original condition....
 because they grow rapidly, absorbing excess mineral nutrients, particularly nitrogen
Nitrogen

Nitrogen is a chemical element that has the symbol N and atomic number 7 and atomic mass 14.00674?. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78% by volume of Earth's atmosphere....
 and phosphates. A cover of duckweeds will reduce evaporation
Evaporation

Evaporation is the slow vaporization of a liquid and the reverse of condensation. A type of phase transition, it is the process by which molecules in a liquid State of matter spontaneously become gaseous ....
 of water compared to a clear surface.

Taxonomy

Classification of the duckweeds in the family Lemnaceae is recognized by most systems of plant classification
List of systems of plant taxonomy

This list of systems of plant taxonomy presents ?taxonomic systems? used in plant classification.A wiktionary:taxonomic system is a coherent whole of alpha taxonomy judgements on circumscription and placement of the considered taxa....
. It is not recognized by the APG II system
APG II system

A modern list of systems of plant taxonomy, the APG II system of plant classification was published in 2003 by the Angiosperm Phylogeny Group, APG, in...
, which places the duckweeds in the aroid family the Araceae
Araceae

Araceae is 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 hood....
 as subfamily Lemnoideae. The genera of duckweeds are: Spirodela
Spirodela

Spirodela is a genus of aquatic plant, commonly called duckweed. Spirodela species are members of the Araceae under the APG II system. They were formerly members of the Lemnaceae....
, Landoltia
Landoltia punctata

Landoltia punctata is a species of duckweed . The genus Landoltia is morphologically intermediate between Lemna and Spirodela. In 1999 D.H....
, Lemna
Lemna

Lemna is a genus of free-floating aquatic plants from the duckweed family. These rapidly-growing plants have found uses as a model system for studies in basic plant biology, in ecotoxicology, in production of biopharmaceuticals, and as a source of animal feeds for agriculture and aquaculture....
, Wolffiella
Wolffiella

Wolffiella is a genus of aquatic plants commonly called duckweeds in the Araceae family . They are rootless and have a keel that allows them to maintain their orientation in the water....
, and Wolffia
Wolffia

Wolffia is a genus of 9 to 11 species which include the smallest flowering plants on Earth. Commonly called watermeal, these aquatic plants resemble specks of cornmeal floating on the water....
.

Genomic Sequencing

In July 2008 the US Department of Energy (DOE) Joint Genome Institute announced the Community Sequencing Program will fund the sequencing the genome of the giant duckweed, Spirodela polyrhiza. This will be a priority project for DOE in 2009. The research is intended to facilitate new biomass and bioenergy programs.

See also

  • Lemna
    Lemna

    Lemna is a genus of free-floating aquatic plants from the duckweed family. These rapidly-growing plants have found uses as a model system for studies in basic plant biology, in ecotoxicology, in production of biopharmaceuticals, and as a source of animal feeds for agriculture and aquaculture....
  • Spirodela
    Spirodela

    Spirodela is a genus of aquatic plant, commonly called duckweed. Spirodela species are members of the Araceae under the APG II system. They were formerly members of the Lemnaceae....
  • Landoltia punctata
    Landoltia punctata

    Landoltia punctata is a species of duckweed . The genus Landoltia is morphologically intermediate between Lemna and Spirodela. In 1999 D.H....


  • Wolffia
    Wolffia

    Wolffia is a genus of 9 to 11 species which include the smallest flowering plants on Earth. Commonly called watermeal, these aquatic plants resemble specks of cornmeal floating on the water....


External links

  • by John W. Cross.
  • and allies
  • in Watson, L. and M.J. Dallwitz (1992 onwards). : descriptions, illustrations, identification, information retrieval. Version: 3 May 2006. http://delta-intkey.com