Blyxa
| Blyxa | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Blyxa | ||||||||||||
| Noronha ex Thouars |
Blyxa ( threadwort ) is a genus of plants in the frog-bite family(Hydrocharitaceae). The eleven to twelve species thrive submerged in fresh water in the tropics to subtropics of Asia , Africa and Australia .
_(20940211225).jpg)
Vegetative characteristics
Blyxa species are perennial, herbaceous plants . They live submerged in fresh water. The stem is short or elongated and erect or runners .
The basal or whorled leaves around the stem are sessile or petiolate. The leaf blades are lanceolate to linear. The midrib and some of the lateral leaf veins are raised.
Generative characteristics
The spathe is tubular, sessile or stalked, divided into two at the tip and with longitudinal veins. The inflorescences usually contain one, sometimes several flowers.
The flowers are unisexual or hermaphroditic. The flowers are radial symmetry and threefold. The three sepals are green, persistent and linear to lanceolate. The three petals are white and longer than the sepals. There are three to nine stamens present. The stamens are slender. There are three stamps. The ovary is linear and tapers into a thin beak. There are numerous ovules . There are three styluses.
The fruit is linear to cylindrical, long and thin. The numerous seeds are elongated spindle-shaped, smooth or studded with thorns and now and then with a thread-like extension at both ends.
Systematics and distribution
The genus Blyxa (from Greek blyzein , 'flow', after the location of some generic representatives) was established in 1806 by Francisco Noroña with Louis Marie Aubert Du Petit-Thouars in his work Genera Nova Madagascariensia 4, 1806. Synonyms for Blyxa Noronha ex Thouars are: Diplosiphon Decne. , Hydrotrophus C.B.Clarke , Enhydrias Ridl. , Blyxopsis Kuntze .
Blyxa species thrive in the tropics and subtropics of Asia, Africa, Madagascar, and Australia.
There are eleven to twelve types:
- Blyxa aubertii Rich. : It is common from Tanzania to Mozambique , Madagascar , Asia and on the Pacific islands.
- Blyxa echinosperma (CBClarke) Hook. f. : It is distributed from tropical and subtropical Asia to northern Australia.
- Blyxa hexandra C.DKCook & Luond : It occurs from Tanzania to Angola .
- Blyxa japonica (Miq.) Maxim. ex ash. & Gürke : It is distributed in two varieties in tropical and subtropical Asia.
- Blyxa javanica Hassk. : It only occurs in Java .
- Blyxa kasaragodensis P.Biju, Josekutty & Augustine : The species first described in 2016 occurs in the Indian state of Kerala .
- Blyxa leiosperma Koidz. : It is common in southern Japan and the Chinese provinces of Anhui , Fujian , Guangdong , Hainan , Jiangxi and Zhejiang .
- Blyxa novoguineensis Hartog : It occurs in Papua New Guinea and maybe also in the Philippines.
- Blyxa octandra (Roxb.) Planch. ex Thwaites : It is spread from India to southern China (Guangdong, Guangxi , Sichuan , Yunnan ) and northern Australia .
- Blyxa quadricostata Hartog : It occurs in Myanmar and Thailand .
- Blyxa radicans Ridl. : It is common in Central Africa to Angola and Tanzania.
- Blyxa senegalensis Dandy : It occurs from Senegal to Guinea .
- Blyxa vietii C.DKCook & Luond : It occurs only in southeastern Vietnam .
literature
- Qingfeng Wang, Youhao Guo, Robert R. Haynes, C. Barre Hellquist: Hydrocharitaceae. : Blyxa , p. 91 and 98-99 - the same text online as the printed work , In: Wu Zheng-yi, Peter H. Raven & Deyuan Hong (eds.): Flora of China. Acoraceae-Cyperaceae. Volume 23, Science Press and Missouri Botanical Garden Press, Beijing and St. Louis 2010, ISBN 978-1-930723-99-3 .
- Christel Kasselmann : aquarium plants. Ulmer Verlag, Stuttgart 1999, ISBN 3-8001-7454-5 , pp. 151 and 446.
supporting documents
- ↑ a b c d e f g h i j k l m n o Rafaël Govaerts (Ed.): Blyxa. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved June 19, 2018.
