Tetragonia
Tetragonia echinata
Tetragonia is a plant genus of the family of Mesembryanthemum plants ( Aizoaceae ). The botanical name of the genus is derived from the Greek words " τέτρα " ( tetra) for four and " γόνος " ( gonos ) for reproduction and refers to the vierwinkligen or four-winged fruits of many species.
Description
The species of the genus Tetragonia are annual to perennial plants with herbaceous or woody branches. Your internodes are usually covered at the juvenile stage to a varying extent with papillae. The leaves are at the base often opposite, but mostly arranged opposite one another. The petiole is short to long, to almost linear and the blade tip often blunted the leaf blade ovate. The epidermis has different shaped papillae.
The individual flowers form small to large cymes or well-defined extended cymes, with each individual carrying a flower bract. This inflorescence then acts often racemose. The cymes often sit on a peduncle from the one appearing in tufts to several flower stalks. The perianth is usually vierzipflig, the ovary inferior. Stamens are usually twice as many as Perigonzipfel available.
The fruits are winged, toothed or knobby, woody nuts with several chambers in which are superimposed the pear- shaped seeds.
Systematics and distribution
The genus Tetragonia is common in tropical areas worldwide. In the southern hemisphere it occurs in drier areas. Many species grow near the sea in the sand, some in rocky terrain.
The first scientific description was published in 1753 by Carolus Linnaeus in Species Plantarum. The holotype is Tetragonia fruticosa. The genus has been divided several times in the past subgenera, sections and series, so in 1803 by Adrian Hardy Haworth, 1828 by Heinrich Gottlieb Ludwig Reichenbach and 1955 by Robert Stephen Adamson ( 1885-1965 ).
After Heidrun Hartmann ( b. 1942 ), the genus Tetragonia include the following types:
- Tetragonia acanthocarpa
- Tetragonia angustifolia
- Tetragonia arbuscula
- Tetragonia arbusculoides
- Tetragonia borealis
- Tetragonia caesia
- Tetragonia calycina
- Tetragonia copiapina
- Tetragonia coronata
- Tetragonia cristata
- Tetragonia crystallina
- Tetragonia decumbens
- Tetragonia diptera
- Tetragonia distorta
- Tetragonia echinata
- Tetragonia erecta
- Tetragonia eremaea
- Tetragonia espinosae
- Tetragonia fruticosa
- Tetragonia galenioides
- Tetragonia glauca
- Tetragonia halimoides
- Tetragonia haworthii
- Tetragonia herbacea
- Tetragonia hirsuta
- Tetragonia implexicoma
- Tetragonia lanceolata
- Tetragonia lasiantha
- Tetragonia macrocarpa
- Tetragonia macroptera
- Tetragonia maritima
- Tetragonia microcarpa
- Tetragonia microptera
- Tetragonia namaquensis
- Tetragonia nigrescens
- Tetragonia ovata
- Tetragonia pedunculata
- Tetragonia pentandra
- Tetragonia pillansii
- Tetragonia portulacoides
- Tetragonia purpurea
- Tetragonia pusilla
- Tetragonia rangeana
- Tetragonia reduplicata
- Tetragonia retusa
- Tetragonia robusta
- Tetragonia rosea
- Tetragonia saligna
- Tetragonia sarcophylla
- Tetragonia schenkii
- Tetragonia sphaerocarpa
- Tetragonia spicata
- Tetragonia tetragonioides
- Tetragonia verrucosa
- Tetragonia vestita
- Tetragonia virgata