Polygonum
Beach knotweed ( Polygonum oxyspermum )
Vogelknöteriche ( Polygonum ) are a genus within the family of the buckwheat family ( Polygonaceae ). The approximately 65 species are distributed almost worldwide.
Description
The Polygonum species grow as annuals to perennial herbaceous plants or subshrubs. The Ochrea is highly variable. The almost always change-constant leaves are always longer than wide.
In one-to many-flowered balls of in the leaf axils or in aged men, racemose or paniculate inflorescences very rarely the flowers are grouped together. The flowers are hermaphrodite in almost all types and rarely unisexual. The perianth consists of five identical, white, greenish or reddish bloom cladding ( tepals ). These are neither keeled nor winged fruit to time. In the flowers, there are four to eight stamens and two or three pen.
The fruits are triangular or lenticular nut fruits, which are always less than twice as long as the perianth and are enclosed or exposed only at the tip.
Occurrence
The genus Polygonum is almost cosmopolitan, that is, it is common to almost all over the world. Exceptions are Africa, tropical South America and the West Indies. The main diversity centers, that is, areas in which most of the species are native, are in Southwest Asia and western North America. Also, the Mediterranean region is relatively rich in species of this genus.
Trivial names
Next to the name smartweed were still a large number of other common names for the genus in use. In Old High German the name for grass * was in use.
Systematics and botanical history
The genus Polygonum was erected in 1753 by Carl Linnaeus in Species Plantarum, 1, p 359. The genus Polygonum L. nom. cons. accordance with the rules of the ICBN preserved ( Vienna ICBN Art 14.9 & App. III). The scientific name Polygonum, although phonetically identical to the ancient Greek polýgonos ( = much producing fertile ), but rather belongs semantically to Gony ( = the knee; internode ), which refers to the typical gnarled stems. A synonym Polygonum L. Duravia ( S. Watson ) Greene
The genus Polygonum belongs to the tribe Polygoneae in the subfamily within the family Polygonaceae Polygonoideae.
Originally, Linnaeus only three species Polygonum latifolium, Polygonum Polygonum angustifolium immersive and classified in the genus Polygonum. Today, these three species no longer belong to the genus Polygonum, but have been transferred to related genera. Intermediate term to grow the number of species of the genus to which Linnaeus had originally set up only three species, to over three hundred species. Today the genus by most authors is divided into several monophyletic genera. There are about 65 species in the genus Polygonum remained.
There are about 65 species of Polygonum, here is a selection:
- Polygonum argyrocoleon Steud. ex Kunze
- Real smartweed ( Polygonum aviculare L.)
- Schachtelhalmartiger knotweed ( Polygonum equisetiforme Sm )
- Upright knotweed ( Polygonum erectum L.)
- Färberknöterich ( Polygonum tinctorum )
- Polygonum hickmanii H.R.Hinds & Rand.Morgan
- Polygonum idaeum Hayek
- Beach knotweed ( Polygonum oxyspermum CAMey. & Bunge ex Ledeb. )
- Polygonum polygaloides Meisn, with the subspecies.: Polygonum polygaloides subsp. kelloggii (Greene) J.C.Hickman
- Polygonum polygaloides Meisn. subsp. polygaloides