Xyridaceae

Xyris complanata

The Xyridaceae are a family of plants that belongs to the order Süßgrasartigen ( Poales ). It includes five genera and about 260 to 300 species.

The Xyridaceae are represented mainly in the tropics and subtropics.

Description

They are mostly perennial, rarely annual, herbaceous plants with rhizomes. The change-constant leaves are concentrated in a basal rosette of leaves or spirally arranged or two lines on the stem. The simple leaves are parallel-veined and have entire margins.

In aged men, racemose or capitate inflorescences with bracts ( bracts ), the flowers are grouped together. The hermaphroditic, flowers are three-fold radial symmetry to strongly zygomorphic. The three (rarely two) sepals are equally diverse. The three petals are usually yellow, rarely white or blue. There are one or two circles, each with three free stamens present in some taxa they are fused with the petals. In some taxa three stamens are reduced to staminodes. The staminodes are kronblattartig many Xyris species. Three carpels are fused into a superior ovaries. The stylus is divided into three parts, ending in one or three scars.

Are formed capsule fruits (rarely one to six ) contain 15 to 90 or more seeds. Most ribbed seeds are winged or wingless.

System

The family is divided into two subfamilies and five genera.

  • Abolbodoideae: With only four genera in northern South America: Abolboda Humb. in Humb. & Bonpl. With about 22 species in northern South America in moist habitats.
  • Achlyphila Maguire & Wurdack: With only one type: Achlyphila disticha Maguire & Wurdack in Venezuela
  • Aratitiyopea lopezii ( L.B.Sm. ) Steyerm. & P.E.Berry in Venezuela
  • Xyris L.: With 225-300 species.

Pictures

Orectanthe sceptrum

Swell

  • The Xyridaceae in APWebsite family. (English)
  • The Xyridaceae at DELTA of L.Watson and MJDallwitz family. (English)
  • H.R. Coleman: Xyris in the flora of Western Australia. Online, 2008 (English )
  • Robert Kral: Xyridaceae in the Flora of North America, Volume 22: Online. (English)
  • Guofang Wu & Robert Kral: Xyridaceae in the Flora of China, Volume 24, p 4: Online. (English)
  • Michael Lock: Xyridaceae, Flora of Tropical East Africa, CRC Press, 1999, ISBN 90-6191-385-3, 9789061913856. Google Books.
  • Lisa M. Campbell: Contributions towards a mono earl of Xyridaceae: A revised nomenclature of Abolboda, in Harvard Papers in Botany 10 (2 ), 2005, pp. 137-145.
  • David John Mabberley: The Plant-Book. A portable dictionary of the higher plants. Cambridge University Press 1987. ISBN 0-521-34060-8
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