Ottelia | |
---|---|
Ottelia alismoides | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Order: | Alismatales |
Family: | Hydrocharitaceae |
Subfamily: | Anacharioideae |
Genus: |
Ottelia Pers. 1805 not R.Hedw. 1806 |
Synonyms [1] | |
|
Ottelia is a genus of an aquatic plant family Hydrocharitaceae described as a genus in 1805. [2] [3] The genus is native to tropical and subtropical regions of Africa, Asia, South America, and Australia. [4] [5]
The genus is highly variable, with a variety of features. [6] It contains aquatic herbs with crowded leaves. Some of the leaves are held on short stems. Others float on long stems. The rooting stem is long. [7]
The flowers are held in a herbaceous bract that is many nerved and has two to six clear ribs. The tubular spathe is shortly divided into two. [7]
Each flower has two rows of a trimerous perianth held above the beak of the ovary. The rigid outer layer is oblong or linear. The larger inner layer is petal-like with a fleshy appendage at the base. [7] There are six or more stamens, often with flattened filaments. [7] The ovary is oblong and beaked with strongly developed placentas dividing it into six chambers that contain many ovules. There are six linear styles that are partially split in two. [7]
The tapering oblong fruits are included in the floral bract and have three to six wings. They contain numerous small, oblong seeds. [7]
It has been suggested that this genus should be divided into two subgenera and four sections: [8]
This genus is found throughout the Paleotropics, from Africa to Asia to Australia and New Caledonia and to Brazil. [8] The areas with the highest diversity occur in central Africa (about 13 species) and south east Asia (about 8 species). [5] [6]They are mostly found growing in lakes, slow flowing creeks and rivers. [9]
Originating in the mid Miocene, this genus now consists of two major clades that correspond to the two major centers of diversity - Africa and Asia. Morphological evidence suggests that this genus originated in Africa. It then spread to South America and Australasia via the ocean, and then from Australasia to Asia. [6]
Global cooling, the development of the East Asian monsoon climate and tectonic movement likely aided diversification in China. The movement of the Yunnan-Guizhou Plateau Pin the liocenehas been suggested to explain the high endemism of Chinese species of Ottelia. [6]
This genus is the second largest in its family (Hydrocharitaceae). [6] The following species are accepted: [1]
The species belonging to this genus are being increasingly negatively impacted by the use and pollution of their water bodies. They have also been declining as a result of climate change. This will continue to occur as climate change accelerates habitat fragmentation and habitat loss due to changing conditions, including increasing water temperatures. [9]
Ottelia | |
---|---|
Ottelia alismoides | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Order: | Alismatales |
Family: | Hydrocharitaceae |
Subfamily: | Anacharioideae |
Genus: |
Ottelia Pers. 1805 not R.Hedw. 1806 |
Synonyms [1] | |
|
Ottelia is a genus of an aquatic plant family Hydrocharitaceae described as a genus in 1805. [2] [3] The genus is native to tropical and subtropical regions of Africa, Asia, South America, and Australia. [4] [5]
The genus is highly variable, with a variety of features. [6] It contains aquatic herbs with crowded leaves. Some of the leaves are held on short stems. Others float on long stems. The rooting stem is long. [7]
The flowers are held in a herbaceous bract that is many nerved and has two to six clear ribs. The tubular spathe is shortly divided into two. [7]
Each flower has two rows of a trimerous perianth held above the beak of the ovary. The rigid outer layer is oblong or linear. The larger inner layer is petal-like with a fleshy appendage at the base. [7] There are six or more stamens, often with flattened filaments. [7] The ovary is oblong and beaked with strongly developed placentas dividing it into six chambers that contain many ovules. There are six linear styles that are partially split in two. [7]
The tapering oblong fruits are included in the floral bract and have three to six wings. They contain numerous small, oblong seeds. [7]
It has been suggested that this genus should be divided into two subgenera and four sections: [8]
This genus is found throughout the Paleotropics, from Africa to Asia to Australia and New Caledonia and to Brazil. [8] The areas with the highest diversity occur in central Africa (about 13 species) and south east Asia (about 8 species). [5] [6]They are mostly found growing in lakes, slow flowing creeks and rivers. [9]
Originating in the mid Miocene, this genus now consists of two major clades that correspond to the two major centers of diversity - Africa and Asia. Morphological evidence suggests that this genus originated in Africa. It then spread to South America and Australasia via the ocean, and then from Australasia to Asia. [6]
Global cooling, the development of the East Asian monsoon climate and tectonic movement likely aided diversification in China. The movement of the Yunnan-Guizhou Plateau Pin the liocenehas been suggested to explain the high endemism of Chinese species of Ottelia. [6]
This genus is the second largest in its family (Hydrocharitaceae). [6] The following species are accepted: [1]
The species belonging to this genus are being increasingly negatively impacted by the use and pollution of their water bodies. They have also been declining as a result of climate change. This will continue to occur as climate change accelerates habitat fragmentation and habitat loss due to changing conditions, including increasing water temperatures. [9]