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Conifers
Conifers () are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All extant conifers are perennial woody plants with secondary growth. The majority are trees, though a few are shrubs. Examples include cedars, Douglas-firs, cypresses, firs, junipers, kauri, larches, pines, hemlocks, redwoods, spruces, and yews.Campbell, Reece, "Phylum Coniferophyta". ''Biology''. 7th ed. 2005. Print. p. 595. As of 2002, Pinophyta contained seven families, 60 to 65 genera, and more than 600 living species. Although the total number of species is relatively small, conifers are ecologically important. They are the dominant plants over large areas of land, most notably the taiga of the Northern Hemisphere, but also in similar cool climates in mountains further south. Boreal conifers have many wintertime adaptations. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gnetophyta
Gnetophyta () is a division of plants (alternatively considered the subclass Gnetidae or order Gnetales), grouped within the gymnosperms (which also includes conifers, cycads, and ginkgos), that consists of some 70 species across the three relict genera: '' Gnetum'' (family Gnetaceae), '' Welwitschia'' (family Welwitschiaceae), and '' Ephedra'' (family Ephedraceae). The earliest unambiguous records of the group date to the Jurassic, and they achieved their highest diversity during the Early Cretaceous. The primary difference between gnetophytes and other gymnosperms is the presence of vessel elements, a system of small tubes (xylem) that transport water within the plant, similar to those found in flowering plants. Because of this, gnetophytes were once thought to be the closest gymnosperm relatives to flowering plants, but more recent molecular studies have brought this hypothesis into question, with many recent phylogenies finding them to be nested within the conifers. Though it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinales
The order Pinales in the division Pinophyta, class Pinopsida, comprises all the extant conifers. The distinguishing characteristic is the reproductive structure known as a cone produced by all Pinales. All of the extant conifers, such as Araucaria, cedar, celery-pine, cypress, fir, juniper, kauri, larch, pine, redwood, spruce, and yew, are included here. Some fossil conifers, however, belong to other distinct orders within the division Pinophyta. Multiple molecular studies indicate this order being paraphyletic with respect to Gnetales, with studies recovering Gnetales as either a sister group to Pinaceae or being more derived than Pinaceae but sister to the rest of the group. Taxonomy History Brown (1825) first discerned that there were two groups of seed plants, distinguished by the form of seed development, based on whether the ovules were exposed, receiving pollen directly, or enclosed, which do not. Shortly afterwards, Brongniart (1828) coined the term '' Phané ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinaceae
The Pinaceae (), or pine family, are conifer trees or shrubs, including many of the well-known conifers of commercial importance such as Cedrus, cedars, firs, Tsuga, hemlocks, Pinyon_pine, piñons, larches, pines and spruces. The family is included in the order Pinales, formerly known as Coniferales. Pinaceae have distinctive cones with woody scales bearing typically two Ovule, ovules, and are supported as monophyletic by both Morphology (biology), morphological trait and genetic analysis. They are the largest extant conifer family in species diversity, with between 220 and 250 species (depending on Taxonomy (biology), taxonomic opinion) in 11 genera, and the second-largest (after Cupressaceae) in geographical range, found in most of the Northern Hemisphere, with the majority of the species in temperate climates, but ranging from subarctic to tropical. The family often forms the dominant component of Boreal forest, boreal, coastal, and montane forests. One species, ''Pinus merkus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltziales
Voltziales is an extinct order of conifers. The group contains the ancestral lineages from which modern conifer groups emerged. Voltzialean conifers are divided into two informal groups, the primitive "walchian conifers" like '' Walchia,'' where the ovuliferous cone is composed of radial shoots and the more advanced "voltzian voltziales", also known as "transitional conifers" where the cone is composed of fertile scales with sessile seeds, like those of modern conifers. Walchian conifers generally grew as small trees. The earliest walchian conifers are known from the Middle Pennsylvanian ( Moscovian). The youngest walchian conifers are known from the Late Permian. The earliest "voltzian voltziales" are known from the late Early Permian ( Kungurian). Modern conifer lineages emerged from voltzialean ancestors from the Late Permian to Jurassic. Voltzialean conifers outside modern groups such as '' Krassilovia''/'' Podozamites'' survived into the Cretaceous The Cretaceous ( ) is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnosperm
The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetophyta, gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in ( and ), and literally means 'naked seeds'. The name is based on the unenclosed condition of their seeds (called ovules in their unfertilized state). The non-encased condition of their seeds contrasts with the seeds and ovules of flowering plants (angiosperms), which are enclosed within an Ovary (botany), ovary. Gymnosperm seeds develop either on the surface of scales or Leaf, leaves, which are often modified to form Conifer cone, cones, or on their own as in Taxus, yew, ''Torreya'', and ''Ginkgo''. The life cycle of a gymnosperm involves alternation of generations, with a dominant diploid sporophyte phase, and a reduced haploid gam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araucariaceae
Araucariaceae is a Family (biology), family of conifers with three living Genus, genera, ''Araucaria'', ''Agathis'', and ''Wollemia''. While the family's native distribution is now largely confined to the Southern Hemisphere, except for a few species of ''Agathis'' in Malesia, it was formerly widespread in the Northern Hemisphere during the Jurassic and Cretaceous periods. Description Members of Araucariaceae are typically extremely tall evergreen trees, reaching heights of or more. They can also grow very large stem diameters; a New Zealand kauri tree (''Agathis australis'') named ''Tāne Mahuta'' ("The Lord of the Forest") has been measured at tall with a diameter at breast height of . Its total wood volume is calculated to be , making it the third-largest conifer after ''Sequoia sempervirens, Sequoia'' and ''Sequoiadendron'' (both from the Cupressaceae subfamily Sequoioideae). The trunks are columnar and have relatively large piths with resinous Cortex (botany), cortices. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spermatophyte
A seed plant or spermatophyte (; New Latin ''spermat-'' and Greek ' (phytón), plant), also known as a phanerogam (taxon Phanerogamae) or a phaenogam (taxon Phaenogamae), is any plant that produces seeds. It is a category of embryophyte (i.e. land plant) that includes most of the familiar land plants, including the flowering plants and the gymnosperms, but not ferns, mosses, or algae. The term ''phanerogam'' or ''phanerogamae'' is derived from the Ancient Greek, Greek (), meaning "visible", in contrast to the term "cryptogam" or "cryptogamae" (, and (), 'to marry'). These terms distinguish those plants with hidden sexual organs (cryptogamae) from those with visible ones (phanerogamae). Description The extant spermatophytes form five divisions, the first four of which are classified as gymnosperms, plants that have unenclosed, "naked seeds": * Cycadophyta, the cycads, a subtropical and tropical group of plants, * Ginkgophyta, which includes a single living species of tree in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conifer Cone
A conifer cone, or in formal botanical usage a strobilus, : strobili, is a seed-bearing organ on gymnosperm plants, especially in conifers and cycads. They are usually woody and variously conic, cylindrical, ovoid, to globular, and have scales and bracts arranged around a central axis, but can be fleshy and berry-like. The cone of Pinophyta (conifer clade) contains the reproductive structures. The woody cone is the female cone, which produces seeds. The male cone, which produces pollen, is usually ephemeral and much less conspicuous even at full maturity. The name "cone" derives from Greek ''konos'' (pine cone), which also gave name to the geometric cone. The individual plates of a cone are known as ''scales''. In conifers where the cone develops over more than one year (such as pines), the first year's growth of a seed scale on the cone, showing up as a protuberance at the end of the two-year-old scale, is called an ''umbo'', while the second year's growth is called th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxaceae
Taxaceae (), commonly called the yew family, is a coniferous family (biology), family which includes six Extant taxon, extant and two extinct genera, and about 30 species of plants, or in older interpretations three genera and 7 to 12 species. Description They are many-branched, small trees and shrubs. The leaves are evergreen, spirally arranged, often twisted at the base to appear 2-ranked. They are linear to lanceolate, and have pale green or white stomatal bands on the undersides. The plants are Plant sexuality, dioecious, or rarely Plant sexuality, monoecious. The catkin like male cones are long, and shed pollen in the early spring. They are sometimes externally only slightly differentiated from the branches. The fertile bracts have 2-8 pollen sacs. The female 'cones' are highly reduced. Only the upper or uppermost bracts are fertile and bear one or rarely two seeds. The ovule usually exceeds the scale, although ovules are sometimes rarely enclosed by it. They may be foun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cupressaceae
Cupressaceae or the cypress family is a family of conifers. The family includes 27–30 genera (17 monotypic), which include the junipers and redwoods, with about 130–140 species in total. They are monoecious, subdioecious or (rarely) dioecious trees and shrubs up to tall. The bark of mature trees is commonly orange- to red-brown and of stringy texture, often flaking or peeling in vertical strips, but smooth, scaly or hard and square-cracked in some species. The family reached its peak of diversity during the Mesozoic era. Description The leaves are arranged either spirally, in decussate pairs (opposite pairs, each pair at 90° to the previous pair) or in decussate whorls of three or four, depending on the genus. On young plants, the leaves are needle-like, becoming small and scale-like on mature plants of many genera; some genera and species retain needle-like leaves throughout their lives. Old leaves are mostly not shed individually, but in small sprays of foliage ( clad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheirolepidiaceae
Cheirolepidiaceae (also spelled Cheirolepidaceae) is an extinct family of conifers. They first appeared in the Triassic, and were a diverse and common group of conifers during most of the Mesozoic era, primarily at low latitudes, where they often formed a dominant element of the vegetation. They are united by the possession of a distinctive pollen type assigned to the form genus ''Classopollis'' (the distinctive characters of which include "distal cryptopore, proximal scar often with filaments, striate equatorial girdle, subequatorial rimula, tegillum (outer tectum of a lesser electron density), and columella-like infratectal elements") The name Frenelopsidaceae (as a separate family) or "frenelopsids" has been used for a group of Cheirolepidiaceae with jointed stems, thick internode cuticles, sheathing leaf bases and reduced free leaf tips. The leaf morphology has been noted as being similar to that of halophyte '' Salicornia.'' Several members of the family appear to have been ada ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cordaitales
Cordaitales are an extinct order of gymnosperms, known from the early Carboniferous to the late Permian. Many Cordaitales had elongated strap-like leaves, resembling some modern-day conifers of the Araucariaceae and Podocarpaceae. They had cone-like reproductive structures reminiscent of those of modern conifers. Some Cordaitales formed large trees that seem to have been particularly abundant on drier ground, in tropical environments. Also, some tall trees but also shrubby and mangrove-like species of Cordaitales seem to have grown in the Carboniferous coal swamps. Cordaitales were also abundant during the Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s .... Common genera from the Carboniferous include '' Mesoxylon'' and '' Cordaixylon''. Other genera are '' Noeggerathio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
