Potamogetonaceae | |
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Potamogeton crispus | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Order: | Alismatales |
Family: | Potamogetonaceae Rchb. [1] |
Genera | |
See text |
The Potamogetonaceae, commonly referred to as the pondweed family, is an aquatic family of monocotyledonous flowering plants. The roughly 110 known species are divided over six genera. [2] The largest genus in the family by far is Potamogeton , which contains about 100 species.
The family has a subcosmopolitan distribution, and is considered to be one of the most important angiosperm groups in the aquatic environment because of its use as food and habitat for aquatic animals. [3]
The Potamogetonaceae are currently placed in the early diverging monocot order Alismatales by the Angiosperm Phylogeny Group. [1] Their concept of the family includes the plants sometimes treated in the separate family Zannichelliaceae, but excludes the genus Ruppia . So circumscribed, the family currently consists of six genera: Althenia , Groenlandia , Lepilaena , Potamogeton , Stuckenia , and Zannichellia , [4] totalling about 120 species of perennial aquatic plants.
Potamogetonaceae | ||||||||||||||||||||||||||||||||||
Marine grasses families: Zosteraceae, Cymodoceaceae, Ruppiaceae and Posidoniaceae. Related families: Potamogetonaceae, Zannichelliaceae (not consistently).
Kubitzki (ed. 1998 [5] ) | Watson & Dallwitz (delta-intkey) [6] | data.kew [7] | APWeb (mobot.org) [8] |
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Zosteraceae | |||
1. Zostera L. | Zostera | Zostera L. | Zostera L. (including Heterozostera den Hartog, Macrozostera Tomlinson & Posluzny, Nanozostera Tomlinson & Posluzny, Zosterella J. K. Small) |
2. Heterozostera den Hartog | Heterozostera | Heterozostera (Setch.) Hartog | (in Zostera ) |
3. Phyllospadix Hook. | Phyllospadix | Phyllospadix Hook. | Phyllospadix J. D. Hooker |
Cymodoceaceae | |||
1. Syringodium Kütz | Syringodium | Syringodium Kutz. | (in Cymodocea ) |
2. Halodule Endl. | Halodule | Halodule Endl. | Halodule Endlicher |
3. Cymodocea König | Cymodocea | Cymodocea K.Koenig (including Phycoschoenus (Asch.) Nakai ) | Cymodocea König (including Amphibolis Agardh ?, Syringodium Kütz. ?, Thalassodendron den Hartog ?) |
4. Amphibolis Agardh | Amphibolis | Amphibolis C.Agardh (including Pectinella J.M.Black) | (in Cymodocea ) |
5. Thalassodendron de Hartog | (name not found) | Thalassodendron Hartog | (in Cymodocea ) |
Ruppiaceae | |||
Ruppia L. | Ruppia | (in Ruppia L. in Potamogetonaceae) | Ruppia L. |
Posidoniaceae | |||
Posidonia König | Posidonia | Posidonia K.Koenig | Posidonia König |
The plants are all aquatic perennial herbs, often with creeping rhizomes and leafy branches. Their leaf blades can be either floating or submerged, and their stems are often joined. No stomata are present on the leaves. The flowers are tetramerous: the floral formula (sepals; petals; stamens; carpels) is [4;0;4;4]. The flowers have no petals. The fruit consists of one to four drupelets or achenes. [12]
The Alismatales (alismatids) are an order of flowering plants including about 4,500 species. Plants assigned to this order are mostly tropical or aquatic. Some grow in fresh water, some in marine habitats. Perhaps the most important food crop in the order is the corm of the taro plant, Colocasia esculenta.
The Malvales are an order of flowering plants. As circumscribed by APG II-system, the order includes about 6000 species within nine families. The order is placed in the eurosids II, which are part of the eudicots.
The Vitaceae are a family of flowering plants, with 14 genera and around 910 known species, including common plants such as grapevines and Virginia creeper. The family name is derived from the genus Vitis.
The Clusiaceae or GuttiferaeJuss. (1789) are a family of plants including 13 genera and ca 750 species. Several former members of Clusiacae are now placed in Calophyllaceae and Hypericaceae. They are mostly trees and shrubs, with milky sap and fruits or capsules for seeds. The family is primarily tropical. More so than many plant families, it shows large variation in plant morphology. According to the APG III, this family belongs to the order Malpighiales.
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.
The Oxalidaceae, or wood sorrel family, are a small family of five genera of herbaceous plants, shrubs and small trees, with the great majority of the 570 species in the genus Oxalis. Members of this family typically have divided leaves, the leaflets showing "sleep movements", spreading open in light and closing in darkness.
Zosteraceae is a family of marine perennial flowering plants found in temperate and subtropical coastal waters, with the highest diversity located around Korea and Japan. Most seagrasses complete their entire life cycle under water, having filamentous pollen especially adapted to dispersion in an aquatic environment and ribbon-like leaves that lack stomata. Seagrasses are herbaceous and have prominent creeping rhizomes. A distinctive characteristic of the family is the presence of characteristic retinacules, which are present in all species except members of Zostera subgenus Zostera.
The Lecythidaceae comprise a family of about 20 genera and 250–300 species of woody plants native to tropical South America, Africa, Asia and Australia.
Chrysobalanaceae is a family of flowering plants, consisting of trees and shrubs in 27 genera and about 700 species of pantropical distribution with a centre of diversity in the Amazon. Some of the species contain silica in their bodies for rigidity and so the mesophyll often has sclerenchymatous idioblasts. The widespread species Chrysobalanus icaco produces a plum-like fruit and the plant is commonly known as the coco plum.
Erythroxylaceae is a family of flowering trees and shrubs consisting of 4 genera and 271 species. The four genera are AneulophusBenth., ErythroxylumP.Browne, NectaropetalumEngl., and PinacopodiumExell & Mendonça. The best-known species are the coca plants, including the species Erythroxylum coca, the source of the substance coca.
Triuridaceae are a family of tropical and subtropical flowering plants, including nine genera with a total of approximately 55 known species. All members lack chlorophyll and are mycoheterotrophic. The heterotrophic lifestyle of these plants has resulted in a loss of xylem vessels and stomata, and a reduction of leaves to scales.
Ruppia, also known as the widgeonweeds, ditch grasses or widgeon grass, is the only extant genus in the family Ruppiaceae, with eight known species. These are aquatic plants widespread over much of the world. The genus name honours Heinrich Bernhard Rupp, a German botanist (1688-1719). They are widespread outside of frigid zones and the tropics.
Najadales is the botanical name of an order of flowering plants. A well-known system that used this name is the Cronquist system (1981), which used this name for an order in subclass Alismatidae with this circumscription:
Cymodoceaceae is a family of flowering plants, sometimes known as the "manatee-grass family", which includes only marine species.
The Anarthriaceae was a family of three genera, Anarthria, Hopkinsia and Lyginia of flowering plants, now included in Restionaceae following APG IV (2016). The family is accepted in the Angiosperm Phylogeny Group's classification system, APG III system, but is not considered a separate family in many other taxonomic systems. The three genera are herbaceous but differ greatly in characteristics.
The Ecdeiocoleaceae comprise a family of flowering plants with two genera and three species. The botanical name has rarely been recognized by taxonomists.
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.
Petiveriaceae is a family of flowering plants formerly included as subfamily Rivinoideae in Phytolaccaceae. The family comprises nine genera, with about 20 known species.