Landoltia punctata
Landoltia punctata | ||||||||||||
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Landoltia punctata , compared with the larger multi-rooted pond lens ( Spirodela polyrhiza ) |
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Systematics | ||||||||||||
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Scientific name of the genus | ||||||||||||
Landoltia | ||||||||||||
Les & DJ Crawford | ||||||||||||
Scientific name of the species | ||||||||||||
Landoltia punctata | ||||||||||||
( G. Meyer ) Les & DJ Crawford |
Spirodela punctata is the only species of the monotypic genus Landoltia from the family of Lemna . It grows on the surface of water.
description
The shoot members are flat or protruding, obovate to elliptical, 1.5 to 8 millimeters long and 1.5 to 3 times as long as they are wide. On the upper side, papillae are usually present along the middle vein . The (rarely one) usually 2 to 7 (rarely up to 12) roots are 0.5 to 7 centimeters in size. The ovary has one or two ovules . The fruit is winged laterally towards the tip. The seeds have 10 to 15 lateral ribs.
The species rarely blooms. The flowering period extends from June to September.
The chromosome number is 2n = 40, 46, 50.
Occurrence
Landoltia punctata occurs in Africa, Asia, Australia, Oceania and North and South America. The species grows in ponds, lake shores, water-filled basins and ditches. It can be found in regions with not too hot summers and mild winters. The vertical distribution ranges from sea level to 2,400 meters.
Systematics
Landoltia punctata was first described by G. Meyer in 1818 as Lemna punctata . In 1999 Les and DJ Crawford placed the species in the monotypical genus Landoltia .
supporting documents
- Heng Li, Elias Landolt : Landoltia . In: Flora of China . Volume 23, 2010 online
Web links
- Landoltia punctata inthe IUCN 2013 Red List of Threatened Species . Posted by: Gupta, AK, 2010. Retrieved January 8, 2014.