Damasonium

Damasonium
	Damasonium californicum
Systematics
Subdivision :	Seed plants (Spermatophytina)
Class :	Bedecktsamer (Magnoliopsida)
	Monocots
Order :	Frog-spoon-like (Alismatales)
Family :	Frog-spoon family (Alismataceae)
Genre :	Damasonium
Scientific name
	Damasonium
	Mill.

Damasonium is a genus of plants from the family of the frog-spoon plants (Alismataceae).

description

Damasonium minus fruits in a whisk

Vegetative characteristics

The Damasonium species are perennial herbaceous plants . The bare parts of the plant are floating or protruding from the water. Rhizomes are usually absent. Stolons are absent. Root tubers are present, but sprout tubers are absent. The roots are not septate.

The leaves are divided into a petiole and a leaf blade. The petiole is triangular. The leaf blade has no transparent spots, is narrowly lanceolate to ovate and its base is rounded to tapering to a point. Basal flaps are absent. The edge of the leaf is whole, the end pointed.

Generative characteristics

The upright, racemose , rarely paniculate inflorescences protruding from the water consist of one to nine whorls. Opposite the pedicels are bracts ; they are much shorter than the flower stalks, lanceolate to ovate-lanceolate and pointed. The flower stalks are ascending to erect.

The hermaphrodite flowers are threefold. The flower base is flat. The sepals are erect and membranous. The petals are white or pink and bitten. There are six stamens . The stamens are dilated and hairless. The 6 to 15 punches are arranged in a single ring. There are one or two ovules . The stylus are terminal.

The fruits are ribbed lengthways and compressed on the sides.

The basic chromosome number is x = 7.

Habit of Damasonium alisma in the habitat

Systematics and distribution

The genus Damasonium was established by Philip Miller in 1754 . Type species is Damasonium alisma Mill. Synonyms for Damasonium Mill. Are Actinocarpus R.Br. , Machaerocarpus Small .

The genus Damasonium is common in Eurasia , Australia and North America .

The genus Damasonium includes six species:

Damasonium alisma Mill .: It iswidespreadfrom Europe to Siberia .
Damasonium bourgaei Coss. : It is common from the Mediterranean to the East Indies .
Damasonium californicum Torr. : It is common from Oregon to central California .
Damasonium constrictum Juz. : It is common from Siberia to Central Asia.
Damasonium minus (R.Br.) Buchenau : It is widespread in southern and eastern Australia.
Damasonium polyspermum Coss. : It is common in the western and central Mediterranean.

supporting documents

literature

Robert R. Haynes, C. Barre Hellquist: Damasonium. In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico . Volume 22: Magnoliophyta: Alismatidae, Arecidae, Commelinidae (in part), and Zingiberidae . Oxford University Press, New York / Oxford a. a. 2000, ISBN 0-19-513729-9 , pp. 10–11 (English, online ).

Individual evidence

↑ Philip Millter: The Gardeners dictionary. 4th corrected and enlarged edition. John and James Rivington, London 1754, digitized .
↑ ^a ^b ^c ^d ^e ^f ^g ^h Rafaël Govaerts (Ed.): Damasonium. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved July 4, 2014.

Web links

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

Damasonium on the IUCN Red List of Threatened Species2009. Retrieved August 18, 2016.

[Miller1754-1] Philip Millter: The Gardeners dictionary. 4th corrected and enlarged edition. John and James Rivington, London 1754, digitized .

[WCSP-2] ↑ ^a ^b ^c ^d ^e ^f ^g ^h Rafaël Govaerts (Ed.): Damasonium. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved July 4, 2014.