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Trochodendraceae
Trochodendraceae is the only family of flowering plants in the order Trochodendrales. It comprises two extant genera, each with a single species along with up to five additional extinct genera and a number of extinct species. The living species are native to south east Asia. The two living species (''Tetracentron sinense'' and ''Trochodendron aralioides'') both have secondary xylem without vessel elements, which is quite rare in angiosperms. As the vessel-free wood suggests primitiveness, these two species have attracted much taxonomic attention. Description ''Tetracentron'' and ''Trochodendron'' are deciduous or evergreen trees, which grow to between tall, with ''Trochodendron'' sometimes sporting umbrella-shaped branches. * Leaves in spirals at the end of the branches (umbrella-like appearance, ''Trochodendron'') or separate ('' Tetracentron''), simple, serrulate or crenulate, with clorantoid teeth, palmately or pinnately divided, brochidodromous or actinodromous, ovate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trochodendron
''Trochodendron'' is a genus of flowering plants with one living species, ''Trochodendron aralioides'', and six extinct species known from the fossil record. It was often considered the sole genus in the family Trochodendraceae, though botanists now also include the distinct genus '' Tetracentron'' in the family. Species * ''Trochodendron aralioides'' *†'' Trochodendron beckii'' *†'' Trochodendron drachukii'' (Infructescence; Ypresian, McAbee Fossil Beds, British Columbia) *†'' Trochodendron evenense'' (Leaves; Miocene, Kamchatka) *†'' Trochodendron infernense'' (Infructescence; Late Palaeocene, Fort Union Formation) *†'' Trochodendron kamtschaticum'' (Infructescence; Miocene, Kamchatka) *†''Trochodendron nastae'' (Leaves; Ypresian, Klondike Mountain Formation, Washington state) *†'' Trochodendron postnastae'' (Leaves; Langhian, Moose Mountain Flora, Oregon) *†'' Trochodendron protoaralioides'' (Leaves; late Miocene, Japan) *†'' Trochodendron rosayi'' (Infructe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraconcavistylon
''Paraconcavistylon'' is an extinct genus of flowering plant in the family Trochodendraceae comprises a single species, ''Paraconcavistylon wehrii''. The genus is known from fossil fruits and leaves found in the early Eocene deposits of northern Washington state, United States, and southern British Columbia, Canada. The species was initially described as a member of the related extinct genus '' Concavistylon'' as ''"Concavistylon" wehrii'', but subsequently moved to the new genus ''Paraconcavistylon'' in 2020 after additional study. Distribution and paleoenvironment ''Paraconcavistylon wehrii'' is known from specimens which were recovered from outcrops of the early Eocene, Ypresian Klondike Mountain Formation in Republic and coeval McAbee Fossil Beds near Cache Creek, British Columbia. The Klondike Mountain Formation and McAbee Fossil sites preserve upland temperate floras which were first interpreted as being microthermal, however further study has shown the floras to be more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trochodendron Aralioides
''Trochodendron aralioides'', sometimes colloquially called wheel tree, is a flowering plant and the sole living species in the genus ''Trochodendron'', which also includes several extinct species. It was also often considered the sole species in the family Trochodendraceae, though botanists now include the distinct genus '' Tetracentron'' in the same family. ''T.aralioides'' is native to Japan, southern Korea and Taiwan. Growing in lower temperate montane mixed forests in Japan, and broad-leaved evergreen forest in the central mountain ranges and Northern parts of Taiwan. Description It is an evergreen tree or large shrub growing to 20 m tall. The leaves are borne in tight spirals at the apex of the year's growth, each leaf leathery dark green, simple broad lanceolate, 6–14 cm long and 3–8 cm broad, with a crenate margin. The flowers are produced 10–20 together in a racemose cyme 5–13 cm diameter; each flower is 15–18 mm diameter, yellowish green, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetracentron
''Tetracentron'' is a genus of flowering plant with a sole living species being '' Tetracentron sinense'' and several extinct species. It was formerly considered the sole genus in the family Tetracentraceae, though it is now included in the family Trochodendraceae together with the genus ''Trochodendron''. Range The living '' Tetracentron sinense'' is native to southern China and the eastern Himalaya, where it grows at altitudes of in a temperate climate; it has no widely used common name in English, though is sometimes called "spur-leaf". Wood vessels ''Tetracentron'' shares with ''Trochodendron'' the feature, very unusual in angiosperms, of lacking vessel elements in its wood. This has long been considered a very primitive character, resulting in the classification of these two genera in a basal position in the angiosperms; however, research in Molecular phylogenetics by the Angiosperm Phylogeny Group and others has shown that these two genera are not basal angiosperms, but b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concavistylon
''Concavistylon'' is an extinct genus of flowering plant in the family Trochodendraceae comprising a single species ''Concavistylon kvacekii''. The genus is known from fossils found in Middle Miocene deposits of central Oregon. A second species '' "Concavistylon" wehrii'' was originally placed in ''Concavistylon'', but subsequently moved to a new genus ''Paraconcavistylon'' in 2020. Distribution and paleoenvironment ''Concavistylon kvacekii'' fossils were found in the Moose Mountain Flora, formerly called the Cascadia flora or Menagerie Wilderness flora, of Linn County, Oregon. The flora is included in the Little Butte Volcanic series outcropping near the town of Cascadia in the central Oregon Cascades. Work on the flora by paleobotanist Jack Wolfe in 1964 gave an estimated age of Early Miocene, this was later revised by Wolfe and Tanai in 1987 to a Late Oligocene estimation. In the descriptive paper naming ''Concavistylon'' Manchester ''et al.'' reported that radioisot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentacentron
''Pentacentron'' is an extinct genus of flowering plant in the family Trochodendraceae, consisting of the single species ''Pentacentron sternhartae''. The genus is known from fossil fruits found in the early Eocene deposits of northern Washington state, United States. ''P. sternhartae'' are possibly the fruits belonging to the extinct trochodendraceous leaves ''Tetracentron hopkinsii''. Distribution and paleoenvironment ''Pentacentron sternhartae'' is known from specimens which are recovered from outcrops of the early Eocene, Ypresian Klondike Mountain Formation in Republic. The Klondike Mountain Formation preserves an upland temperate flora which was first interpreted as being microthermal, however further study has shown the flora to be more mesothermal in nature. The plant community preserved in the Klondike Mountain formation is a mixed conifer–broadleaf forest with large pollen elements of birch and golden larch, but also having notable traces of fir, spruce, cypress, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vessel Element
A vessel element or vessel member (also called trachea or xylem vessel) is one of the cell types found in xylem, the water conducting tissue of plants. Vessel elements are typically found in angiosperms (flowering plants) but absent from most gymnosperms such as conifers. Vessel elements are the main feature distinguishing the "hardwood" of angiosperms from the " softwood" of conifers. Morphology Xylem is the tissue in vascular plants that conducts water (and substances dissolved in it) upwards in a plant. There are two kinds of cell that are involved in the actual transport: tracheids and vessel elements. Tracheids & vessel elements make the tracheary elements of xylem.Vessel elements are the building blocks of vessels, which constitute the major part of the water transporting system in those plants in which they occur. Vessels form an efficient system for transporting water (including necessary minerals) from the root to the leaves and other parts of the plant. In secondary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylem
Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word ''xylem'' is derived from the Ancient Greek word (''xylon''), meaning "wood"; the best-known xylem tissue is wood, though it is found throughout a plant. The term was introduced by Carl Nägeli in 1858. Structure The most distinctive xylem cells are the long tracheary elements that transport water. Tracheids and vessel elements are distinguished by their shape; vessel elements are shorter, and are connected together into long tubes that are called ''vessels''. Xylem also contains two other type of cells: parenchyma and fibers. Xylem can be found: * in vascular bundles, present in non-woody plants and non-woody parts of woody plants * in secondary xylem, laid down by a meristem called the vascular cambium in woody plants * as part of a stelar arrangement n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burl
A burl (American English) or burr (British English) is a tree growth in which the grain has grown in a deformed manner. It is commonly found in the form of a rounded outgrowth on a tree trunk or branch that is filled with small knots from dormant buds. Burl formation is typically a result of some form of stress such as an injury or a viral or fungal infection. Burls yield a very peculiar and highly figured wood sought after in woodworking, and some items may reach high prices on the wood market. Poaching of burl specimens and damaging the trees in the process poses a problem in some areas. Description A burl results from a tree undergoing some form of stress. It may be caused by an injury, virus or fungus. Most burls grow beneath the ground, attached to the roots as a type of malignancy that is generally not discovered until the tree dies or falls over. Such burls sometimes appear as groups of bulbous protrusions connected by a system of rope-like roots. Almost all burl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phyllotaxis
In botany, phyllotaxis () or phyllotaxy is the arrangement of leaf, leaves on a plant stem. Phyllotactic spirals form a distinctive class of patterns in nature. Leaf arrangement The basic leaf#Arrangement on the stem, arrangements of leaves on a stem are opposite and alternate (also known as spiral). Leaves may also be Whorl (botany), whorled if several leaves arise, or appear to arise, from the same level (at the same Node (botany), node) on a stem. With an opposite leaf arrangement, two leaves arise from the stem at the same level (at the same Node (botany), node), on opposite sides of the stem. An opposite leaf pair can be thought of as a whorl of two leaves. With an alternate (spiral) pattern, each leaf arises at a different point (node) on the stem. Distichous phyllotaxis, also called "two-ranked leaf arrangement" is a special case of either opposite or alternate leaf arrangement where the leaves on a stem are arranged in two vertical columns on opposite sides of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes (the archaea and bacteria). By one definition, plants form the clade Viridiplantae (Latin name for "green plants") which is sister of the Glaucophyta, and consists of the green algae and Embryophyta (land plants). The latter includes the flowering plants, conifers and other gymnosperms, ferns and their allies, hornworts, liverworts, and mosses. Most plants are multicellular organisms. Green plants obtain most of their energy from sunlight via photosynthesis by primary chloroplasts that are derived from endosymbiosis with cyanobacteria. Their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic or mycotrophic and have lost the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed on the axis of a plant. The modifications can involve the length and the nature of the internodes and the phyllotaxis, as well as variations in the proportions, compressions, swellings, adnations, connations and reduction of main and secondary axes. One can also define an inflorescence as the reproductive portion of a plant that bears a cluster of flowers in a specific pattern. The stem holding the whole inflorescence is called a peduncle. The major axis (incorrectly referred to as the main stem) above the peduncle bearing the flowers or secondary branches is called the rachis. The stalk of each flower in the inflorescence is called a pedicel. A flower that is not part of an inflorescence is called a solitary flower and its stalk is al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
