Wolffia

Wolffia
	Wolffia arrhiza
Systematics
Class :	Bedecktsamer (Magnoliopsida)
	Monocots
Order :	Frog-spoon-like (Alismatales)
Family :	Arum family (Araceae)
Subfamily :	Duckweed family (Lemnoideae)
Genre :	Wolffia
Scientific name
	Wolffia
	Horkel ex Schleiden

Wolffia is a genus of the subfamily Lemna (Lemnoideae) and the family of Araceae (Araceae).

description

The branches of the plants are freely flooding on or below the water surface. They are symmetrical, spherical, egg-shaped or boat-shaped individually or in pairs. Their top is green, their underside green to transparent; they are never reddish. There is a basal cavity in which daughter scion members are produced. This cavity is not surrounded by a scale at its base. Veins and roots are missing. Daughter members are connected to the mother members by a short, invisible stalk.

The flower rises from a cavity near the center line on the upper side. This cavity is also not surrounded by a scale. The ovary has an ovule . One stamen is two-chambered. One of the seeds is almost smooth.

Occurrence

The genus is almost cosmopolitan .

Illustration of Wolffia brasiliensis

Systematics

The genus Wolffia ("dwarf water lens") was first described in 1844 by Matthias Jacob Schleiden . It was named in honor of Johann Friedrich Wolff (1778–1806) a German doctor, botanist and entomologist. He practiced as a doctor in Schweinfurt and did his doctorate on duckweed ( Lemna ). The genus, which was previously assigned to the Lemnaceae family , comprises eleven species:

Wolffia columbiana , flowering (center right)

Wolffia angusta Landolt : It occurs from Malaysia to Australia.
Rootless dwarf duckweed ( Wolffia arrhiza (L.) Horkel ex Wimm. ): Origin: Europe, Asia and Africa
Wolffia australiana (Benth.) Hartog & Plas : Origin: Australia and New Zealand
Wolffia borealis (Engelm.) Landolt : Home: Canada and USA
Wolffia brasiliensis Wedd. : Homeland: America
Wolffia columbiana H.Karst. : Homeland: America
Wolffia cylindracea Hegelm. : Home: Kenya to South Africa
Wolffia elongata Landolt : Origin: Caribbean and northern South America
Wolffia globosa (Roxb.) Hartog & Plas : Home: tropical and subtropical Asia
Wolffia microscopica (Griff.) In short : Homeland: India, Bangladesh and Pakistan
Wolffia neglecta Landolt ("Overlooked dwarf duckweed"): Homeland: India, Pakistan and Sri Lanka.

supporting documents

Heng Li, Elias Landolt: Wolffia . In: Flora of China . Volume 23, 2010 online .
Christel Kasselmann : aquarium plants. Ulmer Verlag, Stuttgart 1995; 2nd, revised and expanded edition 1999, ISBN 3-8001-7454-5 , p. 438 f.

Individual evidence

↑ Lotte Burkhardt: Directory of eponymous plant names . Botanic Garden and Botanical Museum Berlin, Free University Berlin Berlin 2016. ISBN 978-3-946292-10-4 , page 1095. doi : 10.3372 / epolist2016
↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k Rafaël Govaerts (Ed.): Wolffia. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved August 18, 2014.

Web links

Commons : Wolffia - collection of images, videos and audio files

[Burkhardt-1] Lotte Burkhardt: Directory of eponymous plant names . Botanic Garden and Botanical Museum Berlin, Free University Berlin Berlin 2016. ISBN 978-3-946292-10-4 , page 1095. doi : 10.3372 / epolist2016

[WCSP-2] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k Rafaël Govaerts (Ed.): Wolffia. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved August 18, 2014.