| 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]
Hydrocharitaceae is a flowering plant family including 16 known genera with a total of ca 135 known species, that including a number of species of aquatic plant, for instance the tape-grasses, the well known Canadian waterweed, and frogbit.
Egeria is a genus of three species of aquatic plants in the family Hydrocharitaceae described as a genus in 1849. native to warm-temperate South America.
Ocimum is a genus of aromatic annual and perennial herbs and shrubs in the family Lamiaceae, native to the tropical and warm temperate regions of all 6 inhabited continents, with the greatest number of species in Africa. It is the genus of basil and its best known species are the cooking herb great basil, O. basilicum, and the medicinal herb tulsi, O. tenuiflorum.
Calophyllum is a genus of tropical flowering plants in the family Calophyllaceae. They are mainly distributed in Asia, with some species in Africa, the Americas, Australasia, and the Pacific Islands.
The genus Mitrephora, of family Annonaceae, comprises around 40 species of trees and shrubs found in tropical Asia and northern Australasia. The area of distribution extends from China in the North down to Queensland, Australia in the South. The genus is widely found in southern India and Southeast Asia. It reaches a maximum of diversity in Borneo and the Philippines.
Strophanthus is a genus of flowering plants in the family Apocynaceae, first described as a genus in 1802. It is native primarily to tropical Africa, extending to South Africa, with a few species in Asia from southern India to New Guinea and southern China. The genus name is a compound of the Greek words στροφος (strophos) "twisted" and ανθοσ (anthos) "flower", in reference to the corolla lobes which, in some species - notably S. petersianus - resemble long twisted ribbons or threads and can reach a length of 30–35 cm. This trait, in addition to colouring involving combinations of bright pinks, purples and oranges, combine to make the flowers among the most ornamental in the plant kingdom.
Hydrocharis is a genus of aquatic plants in the family Hydrocharitaceae described as a genus by Carl Linnaeus in 1753. It is widespread across much of Europe and Asia, plus a few scattered locations in Africa. It is also reportedly naturalized in parts of North America.
Pandanaceae is a family of flowering plants native to the tropics and subtropics of the Old World, from West Africa through the Pacific. It contains 982 known species in five genera, of which the type genus, Pandanus, is the most important, with species like Pandanus amaryllifolius and karuka being important sources of food. The family likely originated during the Late Cretaceous.
Clerodendrum is a genus of flowering plants formerly placed in the family Verbenaceae, but now considered to belong to the Lamiaceae (mint) family. Its common names include glorybower, bagflower and bleeding-heart. It is currently classified in the subfamily Ajugoideae, being one of several genera transferred from Verbenaceae to Lamiaceae in the 1990s, based on phylogenetic analysis of morphological and molecular data.
Tetrastigma is a genus of plants in the grape family, Vitaceae. The plants are lianas that climb with tendrils and have palmately compound leaves. Plants are dioecious, with separate male and female plants; female flowers are characterized by their four-lobed stigmas. The species are found in subtropical and tropical regions of Asia, Malaysia, and Australia, where they grow in primary rainforest, gallery forest and monsoon forest and moister woodland. Species of this genus are notable as being the sole hosts of parasitic plants in the family Rafflesiaceae, one of which, Rafflesia arnoldii, produces the largest single flower in the world. Tetrastigma is the donor species for horizontal gene transfer to Sapria and Rafflesia due to multiple gene theft events.
Leea is a genus of plants in the family Vitaceae, subfamily Leeoideae, that are native to parts of central Africa, tropical Asia, Australia and Melanesia. It was previously placed in its own family, Leeaceae, based on morphological differences between it and other Vitaceae genera. These differences include ovule number per locule, carpel number, and the absence or presence of a staminoidal tube and floral disc. Pollen structure has also been examined for taxonomic demarcation, though studies have concluded that the pollen of Leeaceae and Vitaceae suggests the families should remain separate while other studies conclude that Leea should be included in Vitaceae.
The genus Cayratia consists of species of vine plants, typical of the tribe Cayratieae. Some of them are useful, and they are found in tropical and subtropical areas of Asia, Africa, Australia, and islands of the Pacific Ocean.
Althenia is a genus of aquatic plants of the family Potamogetonaceae. This has long been a group of two species in the Mediterranean Europe and South Africa, but in 2016 was revised to include an Australasian relative, Lepilaena.
Ampelocissus is a genus of Vitaceae having 90 or more species found variously in tropical Africa, Asia, Central America, and Oceania. The type species, A. latifolia, was originally treated under its basionym, Vitis latifolia, and was collected from the Indian subcontinent.
Cannabaceae is a small family of flowering plants, known as the hemp family. As now circumscribed, the family includes about 170 species grouped in about 11 genera, including Cannabis (hemp), Humulus (hops) and Celtis (hackberries). Celtis is by far the largest genus, containing about 100 species.
Blyxa is a genus of an aquatic plant of the family Hydrocharitaceae described as a genus in 1806.
Aeollanthus (rocksage) is a genus in the mint family, Lamiaceae. All the species are native to Africa.
Pycnostachys is a genus of plants in the family Lamiaceae, first described in 1826. It is native to sub-Saharan Africa including Madagascar.
Ottelia acuminata, is a plant species endemic to Southern China.