Thalassia (genus)

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Thalassia
Drawing of Thalassia hemprichii

Drawing of Thalassia hemprichii

Systematics
Class : Bedecktsamer (Magnoliopsida)
Monocots
Order : Frog-spoon-like (Alismatales)
Family : Frog bite family (Hydrocharitaceae)
Subfamily : Hydrilloideae
Genre : Thalassia
Scientific name
Thalassia
Banks & Sol. ex KDKoenig
Thalassia testudinum near San Salvador, Bahamas

Thalassia is a genus of plants in the frog-bite family(Hydrocharitaceae).

description

Thalassia species are perennial, herbaceous, marine underwater plants. The rhizome is elongated, creeping and has scales and elongated internodes . Erect, short and leaf-like shoots arise from them. The usually 2 to 6 leaves are two-line and ribbon-like or slightly sickle-shaped. The 9 to 15 leaf veins are parallel and connected to one another by other veins. The leaf base is divorced. The inflorescence is stalked and single-flowered. The 2 Spathas have grown together. The plants are diocesan and the flowers unisexual. Male flowers are stalked. There are three bracts and 3 to 12 stamens . The anthers are 2- to 4-thekig and almost sitting. The pollen grains are spherical and stuck together in pearl-like chains. The female flowers are almost sessile. The ovary is unicameral. Each of the 6 styluses has 2 thread-like scars. The fruits are spherical or elliptical. There are numerous seeds present.

distribution

The genus occurs in the Caribbean and the Gulf of Mexico as well as in the Indian and western Pacific Oceans.

Systematics

Within the genus Thalassia Banks & Sol. ex KDKoenig there are 2 types:

  • Thalassia hemprichii (Ehrenb. Ex Solms) Asch. : It occurs from the Red Sea to the Indian Ocean and the western Pacific.
  • Thalassia testudinum Banks & Sol. ex KDKoenig : It occurs from the southeastern United States to Venezuela and in the Caribbean.

supporting documents

  • Qingfeng Wang, Youhao Guo, Robert R. Haynes, C. Barre Hellquist: Thalassia . In: Flora of China Vol. 23 Hydrocharitaceae , p. 91 ( online )

Individual evidence

  1. ↑ a b Rafaël Govaerts (ed.): Thalassia. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved April 22, 2020.
  2. ^ Robert R. Haynes: Thalassia . In: Flora of North America Vol. 22 Hydrocharitaceae ( online )

Web links

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