HOME
*





Hamamelididae
Hamamelididae is an obsolete botanical name at the rank of subclass. Because some hamamelidid members bear aments (''i.e.'', catkins), this subclass has been formerly known as ''Amentiferae''. Based on molecular phylogeny works, Hamamelididae appears to be a polyphyletic group.Savolainen, V., M. W. Chase, S. B. Hoot, C. M. Morton, D. E. Soltis, C. Bayer, M. F. Fay, A. Y. De Bruijn, S. Sullivan, and Y.-L. Qiu. 2000. Phylogenetics of flowering plants based on combined analysis of plastid ''atpB'' and ''rbcL'' gene sequences. ''Systematic Biology'' 49:306-362. Soltis, D. E. et alii. (28 authors). 2011. "Angiosperm phylogeny: 17 genes, 640 taxa". ''American Journal of Botany'' 98(4):704-730. A well-known system that used the name Hamamelididae is the Cronquist system, although in the disallowed spelling ''Hamamelidae''. In the original 1981 version of this system the circumscription was: * subclass Hamamelidae *: order Trochodendrales *: order Hamamelidales *: order Daphniphylla ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Aments
A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind-pollinated ( anemophilous) but sometimes insect-pollinated (as in ''Salix''). They contain many, usually unisexual flowers, arranged closely along a central stem that is often drooping. They are found in many plant families, including Betulaceae, Fagaceae, Moraceae, and Salicaceae. Occurrence Catkin-bearing plants include many trees or shrubs such as birch, willow, aspen, hickory, sweet chestnut, and sweetfern (''Comptonia''). In many of these plants, only the male flowers form catkins, and the female flowers are single (hazel, oak), a cone (alder), or other types (mulberry). In other plants (such as poplar), both male and female flowers are borne in catkins. In Britain, they can be seen in January or February, when many trees are bare for winter. They can even occur in December. Evolution For some time, catkins were believed to be a key synapomorphy among th ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Catkins
A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind-pollinated (anemophilous) but sometimes insect-pollinated (as in ''Salix''). They contain many, usually unisexual flowers, arranged closely along a central stem that is often drooping. They are found in many plant families, including Betulaceae, Fagaceae, Moraceae, and Salicaceae. Occurrence Catkin-bearing plants include many trees or shrubs such as birch, willow, aspen, hickory, sweet chestnut, and sweetfern (''Comptonia''). In many of these plants, only the male flowers form catkins, and the female flowers are single ( hazel, oak), a cone (alder), or other types ( mulberry). In other plants (such as poplar), both male and female flowers are borne in catkins. In Britain, they can be seen in January or February, when many trees are bare for winter. They can even occur in December. Evolution For some time, catkins were believed to be a key synapomorphy among ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Saxifragales
The Saxifragales (saxifrages) are an order of flowering plants (Angiosperms). They are an extremely diverse group of plants which include trees, shrubs, perennial herbs, succulent and aquatic plants. The degree of diversity in terms of vegetative and floral features makes it difficult to define common features that unify the order. In the Angiosperm Phylogeny Group classification system, the Saxifragales are placed within the major division of flowering plants referred to as eudicots, specifically the core eudicots. This subgroup consists of the Dilleniaceae, superasterids and superrosids. The superrosids in turn have two components, rosids and Saxifragales. The Saxifragales order has undergone considerable revision since its original classification based purely on plant characteristics. The modern classification is based on genetic studies using molecular phylogenetics. There is an extensive fossil record from the Turonian-Campanian (late Cretaceous) time, about 90 millio ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Cronquist System
The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in a series of monographs and texts, including ''The Evolution and Classification of Flowering Plants'' (1968; 2nd edition, 1988) and ''An Integrated System of Classification of Flowering Plants'' (1981) (''see'' Bibliography). Cronquist's system places flowering plants into two broad classes, Magnoliopsida ( dicotyledons) and Liliopsida (monocotyledons). Within these classes, related orders are grouped into subclasses. While the scheme was widely used, in either the original form or in adapted versions, many botanists now use the Angiosperm Phylogeny Group classification for the orders and families of flowering plants, first developed in 1998. The system as laid out in Cronquist's ''An Integrated System of Classification of Flowering Plants'' (1981) counts 64 orders and 321 families in class Magnoliopsida and 19 orders and 65 families in class Liliopsida. ''Th ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Hamamelidaceae
Hamamelidaceae, commonly referred to as the witch-hazel family, is a family of flowering plants in the order Saxifragales. The clade consists of shrubs and small trees positioned within the woody clade of the core Saxifragales. An earlier system, the Cronquist system, recognized Hamamelidaceae in the Hamamelidales order. Description The Hamamelidaceae are distinguishable from other families in the Saxifragales due to the range of floral characteristics that are generally uniform though all genera. Uniform characteristics include stipules borne on stems with leaves often 2-ranked. Genera usually have a two carpel gynoecium, although some species show variation. Other characteristics include a multicellular stigma, with shallow papillae or ridges. Anthers Anther structure and the modes of opening are considered to be one of the most important features in the systematics and evolution of hamamelids. The anthers in Hamamelids are on average shorter than in other families i ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Botanical Name
A botanical name is a formal scientific name conforming to the ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) and, if it concerns a plant cultigen, the additional cultivar or Group epithets must conform to the ''International Code of Nomenclature for Cultivated Plants'' (ICNCP). The code of nomenclature covers "all organisms traditionally treated as algae, fungi, or plants, whether fossil or non-fossil, including blue-green algae (Cyanobacteria), chytrids, oomycetes, slime moulds and photosynthetic protists with their taxonomically related non-photosynthetic groups (but excluding Microsporidia)." The purpose of a formal name is to have a single name that is accepted and used worldwide for a particular plant or plant group. For example, the botanical name ''Bellis perennis'' denotes a plant species which is native to most of the countries of Europe and the Middle East, where it has accumulated various names in many languages. Later, the plant was introduc ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Juglandales
Juglandales is an order of flowering plants. This order was recognised in several systems (e.g. Engler system and Wettstein system). The Cronquist system placed the order in the subclass Hamamelidae, as comprising the families Juglandaceae and Rhoipteleaceae, the latter consisting of only a single species. In the APG II system these two families are united into family Juglandaceae (with the split into two families being optional), and the family is placed in the order Fagales The Fagales are an order of flowering plants, including some of the best-known trees. The order name is derived from genus ''Fagus'', beeches. They belong among the rosid group of dicotyledons. The families and genera currently included are as .... External linksThe Standard Cyclopedia of Horticulture: A Discussion for the Amateur
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Rosids
The rosids are members of a large clade (monophyletic group) of flowering plants, containing about 70,000 species, more than a quarter of all angiosperms. The clade is divided into 16 to 20 orders, depending upon circumscription and classification. These orders, in turn, together comprise about 140 families. Fossil rosids are known from the Cretaceous period. Molecular clock estimates indicate that the rosids originated in the Aptian or Albian stages of the Cretaceous, between 125 and 99.6 million years ago. Today's forests are highly dominated by rosid species, which in turn helped with diversification in many other living lineages. Additionally, rosid herbs and shrubs are also a significant part of arctic/alpine, temperate floras, aquatics, desert plants, and parasites. Name The name is based upon the name "Rosidae", which had usually been understood to be a subclass. In 1967, Armen Takhtajan showed that the correct basis for the name "Rosidae" is a description of a group ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Rank (botany)
In biological classification, taxonomic rank is the relative level of a group of organisms (a taxon) in an ancestral or hereditary hierarchy. A common system consists of species, genus, family, order, class, phylum, kingdom, domain. While older approaches to taxonomic classification were phenomenological, forming groups on the basis of similarities in appearance, organic structure and behaviour, methods based on genetic analysis have opened the road to cladistics. A given rank subsumes under it less general categories, that is, more specific descriptions of life forms. Above it, each rank is classified within more general categories of organisms and groups of organisms related to each other through inheritance of traits or features from common ancestors. The rank of any ''species'' and the description of its ''genus'' is ''basic''; which means that to identify a particular organism, it is usually not necessary to specify ranks other than these first two. Consider a particula ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

APG II System
The APG II system (Angiosperm Phylogeny Group II system) of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Group.Angiosperm Phylogeny Group (2003)An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II.''Botanical Journal of the Linnean Society'' 141(4): 399-436. doi: 10.1046/j.1095-8339.2003.t01-1-00158.x It was a revision of the first APG system, published in 1998, and was superseded in 2009 by a further revision, the APG III system. History APG II was published as: *Angiosperm Phylogeny Group (2003). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II". ''Botanical Journal of the Linnean Society'' 141(4): 399-436. (Available onlineAbstractFull text (HTML)Full text (PDF) doi: 10.1046/j.1095-8339.2003.t01-1-00158.x) Each ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Taxonomic System
Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. Among other things, a taxonomy can be used to organize and index knowledge (stored as documents, articles, videos, etc.), such as in the form of a library classification system, or a search engine taxonomy, so that users can more easily find the information they are searching for. Many taxonomies are hierarchies (and thus, have an intrinsic tree structure), but not all are. Originally, taxonomy referred only to the categorisation of organisms or a particular categorisation of organisms. In a wider, more general sense, it may refer to a categorisation of things or concepts, as well as to the principles underlying such a categorisation. Taxonomy organizes taxonomic units known as "taxa" (singular "taxon")." Taxonomy is different from m ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  




Circumscription
Circumscription may refer to: *Circumscribed circle *Circumscription (logic) Circumscription is a non-monotonic logic created by John McCarthy to formalize the common sense assumption that things are as expected unless otherwise specified. Circumscription was later used by McCarthy in an attempt to solve the frame probl ... * Circumscription (taxonomy) * Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthropologist Robert Carneiro * Electoral district {{disambig ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]