20-651: Apalanthe Appertiella Blyxa Egeria Elodea Enhalus Halophila Hydrilla Hydrocharis Lagarosiphon Limnobium Maidenia Najas Nechamandra Ottelia Stratiotes Thalassia Vallisneria Hydrocharitaceae is a flowering plant family including 16 known genera with a total of ca 135 known species (Christenhusz & Byng 2016), that including
40-446: A number of species of aquatic plant , for instance the tape-grasses , the well known Canadian waterweed , and frogbit . The family includes both freshwater and marine aquatics. They are found throughout the world in a wide variety of habitats, but are primarily tropical. The species are annual or perennial , with a creeping monopodial rhizome with the leaves arranged in two vertical rows, or an erect main shoot with roots at
60-425: A significant problem and it is now considered a noxious weed in these areas. Elodea canadensis , sometimes called American or Canadian water weed or pond weed, is widely known as the generic water weed. The use of these names causes it to be confused with similar-looking plants, like Brazilian elodea ( Egeria densa ) or hydrilla ( Hydrilla verticillata ). American water weed is an attractive aquarium plant and
80-645: Is Anacharis , which serves as a common name in North America. The introduction of some species of Elodea into waterways in parts of Europe, Australia, Africa, Asia, and New Zealand has created a significant problem and it is now considered a noxious weed in these areas. Elodea canadensis , sometimes called American or Canadian water weed or pond weed, is widely known as the generic water weed. The use of these names causes it to be confused with similar-looking plants, like Brazilian elodea ( Egeria densa ) or hydrilla ( Hydrilla verticillata ). American water weed
100-410: Is a good substitute for Brazilian elodea. It can be used for science experiments in classrooms demonstrating how plants use carbon dioxide with the usage of bromothymol blue . The American water weed lives entirely underwater with the exception of small white flowers which bloom at the surface and are attached to the plant by delicate stalks. It produces winter buds from the stem tips that overwinter on
120-482: Is also of economic importance as an attractive and easy to keep aquarium plant, although in the states of Alabama, New Hampshire, New York, and South Carolina it has been deemed Elodea densa an invasive species and is illegal to sell. Chemical methods are ineffective in eradicating Elodea – at best they only slow growth for a season or two. As Elodea spreads into new ecosystems, it experiences rapid growth for 5–6 years and then slows as soil nutrients are used up. Elodea
140-482: Is also of economic importance as an attractive and easy to keep aquarium plant, although in the states of Alabama, New Hampshire, New York, and South Carolina it has been deemed Elodea densa an invasive species and is illegal to sell. Chemical methods are ineffective in eradicating Elodea – at best they only slow growth for a season or two. As Elodea spreads into new ecosystems, it experiences rapid growth for 5–6 years and then slows as soil nutrients are used up. Elodea
160-413: Is an attractive aquarium plant and is a good substitute for Brazilian elodea. It can be used for science experiments in classrooms demonstrating how plants use carbon dioxide with the usage of bromothymol blue . The American water weed lives entirely underwater with the exception of small white flowers which bloom at the surface and are attached to the plant by delicate stalks. It produces winter buds from
180-412: Is that through vegetative reproduction via fragments, mechanical removal methods can contribute to the spread of the plant. Torn fragments can be transported downstream or are introduced to new environments via attachment to boats and anchor chains. Egeria (plant) Elodea is a genus of eight species of aquatic plants often called the waterweeds described as a genus in 1803. Classified in
200-584: Is threatening aquatic environments across Europe. Chemicals may be used in places that cause undue economic concerns, but very few aquatic herbicides are registered for aquatic use in the EU. Fluridone , the most commonly used aquatic herbicide is highly effective against Hydrilla, but only marginally effective against Elodea, especially at lower use rates. The plants can also be removed from lakes and rivers mechanically. They are extracted either by hand or by using rakes, chains, mowing boats or weed buckets. The problem
220-539: Is threatening aquatic environments across Europe. Chemicals may be used in places that cause undue economic concerns, but very few aquatic herbicides are registered for aquatic use in the EU. Fluridone , the most commonly used aquatic herbicide is highly effective against Hydrilla, but only marginally effective against Elodea, especially at lower use rates. The plants can also be removed from lakes and rivers mechanically. They are extracted either by hand or by using rakes, chains, mowing boats or weed buckets. The problem
SECTION 10
#1732872369005240-589: The base and spirally arranged or whorled leaves. The leaves are simple and usually found submerged, though they may be found floating or partially emerse . As with many aquatics they can be quite variable in shape – from linear to orbicular , with or without a petiole , and with or without a sheathing base. The flowers are arranged in a forked, spathe-like bract or between two opposite bracts. They are usually irregular, though in some case they may be slightly irregular, and either bisexual or unisexual. The perianth segments are in 1 or 2 series of 2–3 free segments;
260-699: The centre of the ovary or are incompletely developed. Fruits are globular to linear, dry or pulpy, dehiscent or more usually indehiscent and opening by decay of the pericarp . Seeds are normally numerous with straight embryos and no endosperm . Pollination can be extremely specialised. The most recent phylogenetic treatment of the family recognizes four subfamilies . Enhalus Thalassia Halophila Vallisneria Nechamandra Hydrilla Najas Limnobium Hydrocharis Elodea Egeria Appertiella Ottelia Blyxa Lagarosiphon Stratiotes Some species have become established ornamental plants , and subsequently serious weeds in
280-489: The frog's-bit family ( Hydrocharitaceae ), Elodea is native to the Americas and is also widely used as aquarium vegetation and laboratory demonstrations of cellular activities. It lives in fresh water. An older name for this genus is Anacharis , which serves as a common name in North America. The introduction of some species of Elodea into waterways in parts of Europe, Australia, Africa, Asia, and New Zealand has created
300-460: The inner series when present are usually showy and petal-like. Stamens 1–numerous, in 1 or more series; the inner ones sometimes sterile. pollen grains are globular and free but in the marine genera ( Thalassia and Halophila ) – the pollen grains are carried in chains, like strings of beads. The ovary is inferior with 2–15 united carpels containing a single locule with numerous ovules on parietal placentas which either protrude nearly to
320-528: The lake bottom. It also often overwinters as an evergreen plant in mild climates. In the Autumn, leafy stalks will detach from the parent plant, float away, root, and start new plants. This is the American water weed's most important method of spreading, while seed production plays a relatively minor role. Silty sediments and water rich in nutrients favor the growth of American water weed in nutrient-rich lakes. However,
340-533: The plants will grow in a wide range of conditions, from very shallow to deep water, and in many sediment types. It can even continue to grow uprooted, as floating fragments. It is found throughout temperate North America, where it is one of the most common aquatic plants. American water weed is an important part of lake ecosystems . It provides good habitat for many aquatic invertebrates and cover for young fish and amphibians. Waterfowl, especially ducks, as well as beaver, muskrat and aquatic turtles eat this plant. It
360-533: The plants will grow in a wide range of conditions, from very shallow to deep water, and in many sediment types. It can even continue to grow uprooted, as floating fragments. It is found throughout temperate North America, where it is one of the most common aquatic plants. American water weed is an important part of lake ecosystems . It provides good habitat for many aquatic invertebrates and cover for young fish and amphibians. Waterfowl, especially ducks, as well as beaver, muskrat and aquatic turtles eat this plant. It
380-461: The stem tips that overwinter on the lake bottom. It also often overwinters as an evergreen plant in mild climates. In the Autumn, leafy stalks will detach from the parent plant, float away, root, and start new plants. This is the American water weed's most important method of spreading, while seed production plays a relatively minor role. Silty sediments and water rich in nutrients favor the growth of American water weed in nutrient-rich lakes. However,
400-504: The wild (especially Egeria , Elodea and Hydrilla ). Apalanthe Elodea is a genus of eight species of aquatic plants often called the waterweeds described as a genus in 1803. Classified in the frog's-bit family ( Hydrocharitaceae ), Elodea is native to the Americas and is also widely used as aquarium vegetation and laboratory demonstrations of cellular activities. It lives in fresh water. An older name for this genus
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