Tetrachondraceae
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The Tetrachondraceae are a family of plants in the order of the mint-like family (Lamiales).
description
Vegetative characteristics
Tetrachondraceae are small, creeping to erect, perennial herbaceous plants . Two types are succulents that contain essential oils . One species is an aquatic plant . The opposite leaves are small, simple, leathery and usually only short stalked. The leaf margins are tiny serrated.
Generative characteristics
The flowers are individually either terminal or in the leaf axils. The hermaphrodite, very small flowers are radial symmetry and fourfold with double perianth (perianth). The four sepals are fused bell-shaped. The four white petals are fused tubular or bell-shaped. They only have a circle with four fertile stamens that are free from each other. Two carpels are fused to form an upper or semi- lower ovary with a stylus with a small scar . The ovary is secondarily divided by a false septum, creating four chambers.
Either a two-chamber capsule fruit or a fruit from four nuts is formed.
Systematics and distribution
Tetrachondra was classified in the Boraginaceae or Lamiaceae . Polypremum was always placed near the Loganiaceae. The Tetrachondraceae family was established in 1924 by Richard Wettstein .
The family Tetrachondraceae has a disjoint area : on the one hand New Zealand and Australia ; on the other hand Patagonia and from the southern USA to South America .
The Tetrachondraceae family includes only two genera and about three species:
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Polypremum
L .: It contains only one species:
- Polypremum procumbens L .: Their homeland extends from the southern USA to South America.
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Tetrachondra Petrie ex Oliv. : The only two types have the typical distribution corresponding to the urcontinent Gondwana :
- Tetrachondra hamiltonii Petrie ex Oliv. : The home is New Zealand.
- Tetrachondra patagonica Skottsb. : The home is southern Argentina to Tierra del Fuego .
swell
- The Tetrachondraceae family on the AP website . (Sections systematics and description)
- The Tetrachondraceae family at DELTA . (Section description)
- Entry on New South Wales Flora Online . (Section description)
- Tetrachondraceae in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved March 13, 2014.
Individual evidence
- ↑ a b Rafaël Govaerts (Ed.): Tetrachondraceae. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved November 30, 2018.
Web links
- Description of the family of Carlos Durán-Espinosa, Instituto de Ecología, AC, Xalapa, Ver., Centro de Investigaciones Tropicales. ( Memento of March 6, 2009 in the Internet Archive ) (Spanish; PDF file; 792 kB)
Map with all linked sites: