A turion (from Latin turio meaning "shoot") is a type of bud that is capable of growing into a complete plant. A turion may be an underground bud. [1] Many members of the genus Epilobium are known to produce turions at or below ground level. [2]
Some aquatic plant species produce overwintering turions, especially in the genera Potamogeton , Myriophyllum , Aldrovanda and Utricularia . These plants produce turions in response to unfavourable conditions such as decreasing day-length or reducing temperature.
They are derived from modified shoot apices and are often rich in starch and sugars enabling them to act as storage organs. Although they are hardy (frost resistant), it is probable that their principal adaptation is their ability to sink to the bottom of a pond or lake when the water freezes. Because water expands anomalously at lower temperatures, water at 4 °C (39 °F) is denser than colder water, and thus stays at the bottom of the pond or lake. Turions overwinter in this denser, warmer water before rising again in the spring. Some turions of aquatic plants such as Potamogeton crispus also exhibit drought resistance, allowing them to survive in temporary pools. [3]
Aquatic plants are plants that have adapted to living in aquatic environments. They are also referred to as hydrophytes or macrophytes to distinguish them from algae and other microphytes. A macrophyte is a plant that grows in or near water and is either emergent, submergent, or floating. In lakes and rivers, macrophytes provide cover for fish, substrate for aquatic invertebrates, produce oxygen, and act as food for some fish and wildlife.
Utricularia, commonly and collectively called the bladderworts, is a genus of carnivorous plants consisting of approximately 233 species. They occur in fresh water and wet soil as terrestrial or aquatic species across every continent except Antarctica. Utricularia are cultivated for their flowers, which are often compared with those of snapdragons and orchids, especially amongst carnivorous plant enthusiasts.
Genlisea is a genus of carnivorous plants also known as corkscrew plants. The 30 or so species grow in wet terrestrial to semi-aquatic environments distributed throughout Africa and Central and South America. The plants use highly modified underground leaves to attract, trap and digest minute microfauna, particularly protozoans. Although suggested a century earlier by Charles Darwin, carnivory in the genus was not proven until 1998.
Aldrovanda vesiculosa, commonly known as the waterwheel plant, is the sole extant species in the flowering plant genus Aldrovanda of the family Droseraceae. The plant captures small aquatic invertebrates using traps similar to those of the Venus flytrap. The traps are arranged in whorls around a central, free-floating stem, giving rise to the common name. This is one of the few plant species capable of rapid movement.
Potamogeton is a genus of aquatic, mostly freshwater, plants of the family Potamogetonaceae. Most are known by the common name pondweed, although many unrelated plants may be called pondweed, such as Canadian pondweed. The genus name means "river neighbor", originating from the Greek potamos (river) and geiton (neighbor).
Aldrovanda is a genus of carnivorous plants encompassing one extant species and numerous extinct taxa. The genus is named in honor of the Italian naturalist Ulisse Aldrovandi, the founder of the Botanical Garden of Bologna, Orto Botanico dell'Università di Bologna. Aldrovanda vesiculosa has been reported from scattered locations in Europe, Asia, Africa, and Australia.
Potamogeton crispus, the crisp-leaved pondweed, curly pondweed, curly-leaf pondweed or curled pondweed, is a species of aquatic plant (hydrophyte) native to Eurasia but an introduced species and often a noxious weed in North America.
Utricularia resupinata, popularly known as lavender bladderwort or northeastern bladderwort, is a small perennial subaquatic carnivorous plant that belongs to the genus Utricularia. It is native to eastern Canada, the United States, and Central America. This plant species has an interesting etymology, growth pattern, ecology, and research history. As a plant that is threatened or endangered in many of the States where it is found, it is a candidate for sound conservation efforts.
Hibernaculum is the term often applied to a winter bud of certain aquatic plants, such as the bladderworts (Utricularia). The buds are heavier than water, and, being developed at the approach of cold weather, they become detached, sink to the bottom of the pond, and thus survive the winter. In the spring, they enlarge, developing air spaces, rise to the surface, and reproduce their species.
Myriophyllum verticillatum, the whorl-leaf watermilfoil or whorled water-milfoil, is a native to much of North America, North Africa, and Eurasia. It closely resembles another native milfoil, called northern water milfoil Whorled water milfoil is also easily confused with four types of invasive milfoils: Eurasian water milfoil, Variable water-milfoil, Parrot feather, and hybrid water milfoil.
Potamogeton alpinus is a species of perennial aquatic plant known by the common names alpine pondweed and red pondweed. It is widespread in the northern hemisphere in both rivers and lakes with good water quality.
Potamogeton foliosus is a species of aquatic plant known by the common name leafy pondweed. It is native to nearly all of North America and parts of Central America, where it grows in water bodies such as ponds, lakes, ditches, and slow-moving streams. It has been reported from every state in the United States except Hawaii as well as from every Canadian province and territory except Newfoundland and Nunavut.
Potamogeton pusillus is a species of aquatic plant known by the common names small pondweed, lesser pondweed or least pondweed. It occurs in standing and slow-flowing freshwater habitats throughout the Northern Hemisphere.
Potamogeton compressus is a species of aquatic plant known by the common names grass-wrack pondweed, flatstem pondweed and eel-grass pondweed.
Spirodela polyrhiza is a species of duckweed known by the common names common duckmeat, greater duckweed, great duckmeat, common duckweed, and duckmeat. It can be found nearly worldwide in many types of freshwater habitat.
Potamogeton obtusifolius, known as blunt-leaved pondweed, is an aquatic plant in the genus Potamogeton. It grows mainly in mesotrophic to eutrophic lakes, ponds and ditches, rarely in brackish water. It occurs primarily in Central Europe, the British Isles, Fennoscandia and eastern North America.
In botany, perennation is the ability of organisms, particularly plants, to survive from one germinating season to another, especially under unfavourable conditions such as drought or winter cold. It typically involves development of a perennating organ, which stores enough nutrients to sustain the organism during the unfavourable season, and develops into one or more new plants the following year. Common forms of perennating organs are storage organs, and buds. Perennation is closely related with vegetative reproduction, as the organisms commonly use the same organs for both survival and reproduction.
Potamogeton berchtoldii, common name small pondweed, is an aquatic plant.
Potamogeton friesii, known as flat-stalked pondweed, or Fries' pondweed, is an aquatic plant in the genus Potamogeton. It grows mainly in mesotrophic to eutrophic rivers, lakes, ponds and ditches, rarely in brackish water. It occurs in North America, Europe, western Asia and a few scattered locations elsewhere in Asia.
Pond life is an umbrella term for all life forms found in ponds. Although there is considerable overlap with the species lists for small lakes and even slow flowing rivers, pond life includes some species not found elsewhere and as a biome it represents a unique assemblages of species.
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