Taxodium
Overview
Taxodium is a genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of one to three species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 (depending on taxonomic
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

 opinion) of extremely flood
Flood
A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...

-tolerant conifers in the cypress family, Cupressaceae
Cupressaceae
The Cupressaceae or cypress family is a conifer family with worldwide distribution. The family includes 27 to 30 genera , which include the junipers and redwoods, with about 130-140 species in total. They are monoecious, subdioecious or dioecious trees and shrubs from 1-116 m tall...

. The generic name is derived from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 word taxus, meaning "yew
Taxus
Taxus is a genus of yews, small coniferous trees or shrubs in the yew family Taxaceae. They are relatively slow-growing and can be very long-lived, and reach heights of 1-40 m, with trunk diameters of up to 4 m...

", and the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 word εἶδος (eidos), meaning "similar to." Within the family, Taxodium is most closely related to Chinese Swamp Cypress
Glyptostrobus
Glyptostrobus, is a small genus of conifers in the family Cupressaceae. The sole living species, Glyptostrobus pensilis, is native to subtropical southeastern China, from Fujian west to southeast Yunnan, and also very locally in northern Vietnam and Borikhamxai Province of eastern Lao PDR near the...

 (Glyptostrobus pensilis) and Sugi
Cryptomeria
Cryptomeria is a monotypic genus of conifer in the cypress family Cupressaceae formerly belonging to the family Taxodiaceae; it includes only one species, Cryptomeria japonica . It is endemic to Japan, where it is known as Sugi...

 (Cryptomeria japonica).

Species of Taxodium occur in the southern part of the North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

n continent and are deciduous
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...

 in the north and semi-evergreen to evergreen
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...

 in the south.
Unanswered Questions
Encyclopedia
Taxodium is a genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of one to three species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 (depending on taxonomic
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

 opinion) of extremely flood
Flood
A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...

-tolerant conifers in the cypress family, Cupressaceae
Cupressaceae
The Cupressaceae or cypress family is a conifer family with worldwide distribution. The family includes 27 to 30 genera , which include the junipers and redwoods, with about 130-140 species in total. They are monoecious, subdioecious or dioecious trees and shrubs from 1-116 m tall...

. The generic name is derived from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 word taxus, meaning "yew
Taxus
Taxus is a genus of yews, small coniferous trees or shrubs in the yew family Taxaceae. They are relatively slow-growing and can be very long-lived, and reach heights of 1-40 m, with trunk diameters of up to 4 m...

", and the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 word εἶδος (eidos), meaning "similar to." Within the family, Taxodium is most closely related to Chinese Swamp Cypress
Glyptostrobus
Glyptostrobus, is a small genus of conifers in the family Cupressaceae. The sole living species, Glyptostrobus pensilis, is native to subtropical southeastern China, from Fujian west to southeast Yunnan, and also very locally in northern Vietnam and Borikhamxai Province of eastern Lao PDR near the...

 (Glyptostrobus pensilis) and Sugi
Cryptomeria
Cryptomeria is a monotypic genus of conifer in the cypress family Cupressaceae formerly belonging to the family Taxodiaceae; it includes only one species, Cryptomeria japonica . It is endemic to Japan, where it is known as Sugi...

 (Cryptomeria japonica).

Species of Taxodium occur in the southern part of the North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

n continent and are deciduous
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...

 in the north and semi-evergreen to evergreen
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...

 in the south. They are large tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

s, reaching 100–150 ft (30.5–45.7 m) tall and 2–3 m (6.6–9.8 ft) (exceptionally 11 m (36.1 ft)) trunk diameter. The needle-like leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

, 0.5–2 cm (0.196850393700787–0.78740157480315 in) long, are borne spirally on the shoot
Shoot
Shoots are new plant growth, they can include stems, flowering stems with flower buds, and leaves. The new growth from seed germination that grows upward is a shoot where leaves will develop...

s, twisted at the base so as to appear in two flat rows on either side of the shoot. The cones
Conifer cone
A cone is an organ on plants in the division Pinophyta that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity...

 are globose, 2–3.5 cm (0.78740157480315–1.4 in) diameter, with 10-25 scales, each scale with 1-2 seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

s; they are mature in 7–9 months after pollination
Pollination
Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...

, when they disintegrate to release the seeds. The male (pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...

) cones are produced in pendulous raceme
Raceme
A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...

s, and shed their pollen in early spring.

Species

The three taxa
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...

 of Taxodium are treated here as distinct species, though some botanists treat them in just one or two species, with the others considered as varieties of the first described. The three are distinct in ecology
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...

, growing in different environments, but hybridise where they meet.
  • Taxodium ascendens
    Taxodium ascendens
    Taxodium ascendens, also known as Pond Cypress, is a deciduous conifer of the genus Taxodium, native to North America. Many botanists treat it as a variety of Bald Cypress, Taxodium distichum Taxodium ascendens, also known as Pond Cypress, is a deciduous conifer of the genus Taxodium, native to...

    Brongn.
    Adolphe Theodore Brongniart
    Adolphe-Théodore Brongniart was a French botanist. He was the son of the geologist Alexandre Brongniart and grandson of the architect, Alexandre-Théodore Brongniart. Brongniart's pioneering work on the relationships between extinct and existing plants has earned him the title of father of...

    – Pond Cypress

The Pond Cypress occurs within the range of Bald Cypress, but only on the southeastern coastal plain from North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...

 to Louisiana
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...

. It occurs in still blackwater rivers, ponds and swamps without silt
Silt
Silt is granular material of a size somewhere between sand and clay whose mineral origin is quartz and feldspar. Silt may occur as a soil or as suspended sediment in a surface water body...

-rich flood deposits.
  • Taxodium distichum
    Taxodium distichum
    Taxodium distichum is a species of conifer native to the southeastern United States.-Characteristics:...

    (L.) Rich.
    Louis Claude Richard
    Louis Claude Marie Richard was a French botanist.Richard was born at Versailles. Between 1781 and 1789 he collected botanical specimens in Central America and the West Indies...

    – Bald Cypress

The most familiar species in the genus is the Bald Cypress, native to much of the southeastern
Southeastern United States
The Southeastern United States, colloquially referred to as the Southeast, is the eastern portion of the Southern United States. It is one of the most populous regions in the United States of America....

 United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, from Delaware
Delaware
Delaware is a U.S. state located on the Atlantic Coast in the Mid-Atlantic region of the United States. It is bordered to the south and west by Maryland, and to the north by Pennsylvania...

 to Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

, especially Louisiana
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...

 and inland up the Mississippi River
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

 to southern Indiana
Indiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...

. It occurs mainly along rivers with silt-rich flood deposits.
  • Taxodium mucronatum
    Taxodium mucronatum
    Taxodium mucronatum, also known as Montezuma Cypress, Sabino, or Ahuehuete is a species of Taxodium native to much of Mexico , and also the Rio Grande Valley in southernmost Texas, USA as well as Huehuetenango Department in Guatemala...

    Ten.
    Michele Tenore
    Michele Tenore was an Italian botanist active in Naples, Italy.Tenore studied at the University of Naples, receiving his medical degree in 1800...

    – Montezuma Cypress, Ahuehuete

The Montezuma Cypress occurs from the Lower Rio Grande Valley
Rio Grande Valley
The Rio Grande Valley or the Lower Rio Grande Valley, informally called The Valley, is an area located in the southernmost tip of South Texas...

 south to the highlands of southern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

, and differs from the other two species in being substantially evergreen. A specimen in Santa María del Tule, Oaxaca
Santa María del Tule, Oaxaca
Santa María del Tule is a town and a municipality in the Mexican state of Oaxaca.It is part of the Centro District in the Valles Centrales region.It is located SE of the city of Oaxaca on Highway 190, passing the city and ruins of Mitla...

, the Árbol del Tule
Árbol del Tule
El Árbol del Tule is a tree located in the church grounds in the town center of Santa María del Tule in the Mexican state of Oaxaca, approximately 9 km east of the city of Oaxaca on the road to Mitla. It is a Montezuma Cypress , or Ahuehuete...

, is 43 m (141.1 ft) tall and has the greatest trunk thickness of all trees, 11.42 m (37.5 ft) in diameter. It is a riparian
Riparian zone
A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the fifteen terrestrial biomes of the earth. Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by...

 tree, occurring on the banks of streams and rivers, not in swamps like the Bald and Pond Cypresses.

Formerly placed here

  • Glyptostrobus pensilis
    Glyptostrobus pensilis
    Glyptostrobus pensilis, also known as Chinese Swamp Cypress, is the sole living species in the genus Glyptostrobus. It is native to subtropical southeastern China, from Fujian west to southeast Yunnan, and also very locally in northern Vietnam....

    (Staunton ex D.Don) K.Koch (as T. japonicum var. heterophyllum Brongn.)
  • Sequoia sempervirens (D.Don) Endl. (as T. sempervirens D.Don)

Uses

The trees are especially prized for their wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

, of which the heartwood is extremely rot
Decomposition
Decomposition is the process by which organic material is broken down into simpler forms of matter. The process is essential for recycling the finite matter that occupies physical space in the biome. Bodies of living organisms begin to decompose shortly after death...

 and termite
Termite
Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order Isoptera , but are now accepted as the epifamily Termitoidae, of the cockroach order Blattodea...

 resistant. The heartwood contains a sesquiterpene
Sesquiterpene
Sesquiterpenes are a class of terpenes that consist of three isoprene units and have the molecular formula C15H24. Like monoterpenes, sesquiterpenes may be acyclic or contain rings, including many unique combinations...

 called cypressene, which acts as a natural preservative
Wood preservation
All measures that are taken to ensure a long life of wood fall under the definition wood preservation . Apart from structural wood preservation measures, there are a number of different preservatives and processes that can extend the life of wood, timber, wood structures or engineered wood...

. It takes decades for cypressene to accumulate in the wood, so lumber taken from old-growth trees is more rot resistant than that from second-growth trees. However, age also increases susceptibility to Pecky Rot fungus (Stereum
Stereum
Stereum is type genus of the Stereaceae family of fungi, in the Russulales order. Until recently, the genus was classified in the Corticiaceae family, of the Corticiales order. However, it was given its own family as a result of the split-up of the Corticiales. Common names for species of this...

 taxodii
), which attacks the heartwood and causes some damaged trees to become hollow and thus useless for timber. Bald Cypress wood was much used in former days in the southeastern United States for roof shingle
Roof shingle
Roof shingles are a roof covering consisting of individual overlapping elements. These elements are typically flat rectangular shapes laid in rows from the bottom edge of the roof up, with each successive higher row overlapping the joints in the row below...

s. The shredded bark
Bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...

 of these trees is used as a mulch
Mulch
In agriculture and gardening, is a protective cover placed over the soil to retain moisture, reduce erosion, provide nutrients, and suppress weed growth and seed germination. Mulching in gardens and landscaping mimics the leaf cover that is found on forest floors....

, although the current harvest rate for this product is unsustainable and is causing substantial environment
Natural environment
The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....

al damage especially in the south where cutting boundaries are not being followed.

Evolution

In earth's history Taxodium was widespread. It is known since the Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 and can be found as fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 e.g. in layers from Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...

times.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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