Strobiloideae

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The Strobiloideae are an obsolete taxonomic name, a subclass of both Monocotyledons and Dicotyledons proposed by Charles Bessey in 1915 in his taxonomic classification of plants. [1] In this sense by not being unique it breaks the rules of botanical nomenclature as currently used, however Bessey actually used a qualifying hyphenation (Alternifoliae-Strobiloideae and Oppositifoliae-Strobiloideae), a distinction not always recognised in reference to this scheme.

Taxon Group of one or more populations of an organism or organisms which have distinguishing charachterisics in common

In biology, a taxon is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is not uncommon, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping.

A system of plant taxonomy, the Bessey system was published by Charles Bessey in 1915.

Botanical nomenclature is the formal, scientific naming of plants. It is related to, but distinct from taxonomy. Plant taxonomy is concerned with grouping and classifying plants; botanical nomenclature then provides names for the results of this process. The starting point for modern botanical nomenclature is Linnaeus' Species Plantarum of 1753. Botanical nomenclature is governed by the International Code of Nomenclature for algae, fungi, and plants (ICN), which replaces the International Code of Botanical Nomenclature (ICBN). Fossil plants are also covered by the code of nomenclature.

Contents

Bessey believed in the strobiloid theory of plant evolution that postulated that the Angiospermae (flowering plants) originated from Cycadophyta, and that flowers originated from a primitive vegetative shoot that developed into a structure with perianth, stamens and carpels. From this arose two lines, the Strobiloideae (or Ranalian line) with connation of like parts and the Cotyloideae (or Rosalian line) with connation of unlike parts, which he assigned as the two subclasses of monocots (called Alternifoliae by Bessey), but also of dicots (called Oppositifoliae by Bessey).

A strobilus is a structure present on many land plant species consisting of sporangia-bearing structures densely aggregated along a stem. Strobili are often called cones, but many botanists restrict the use of the term cone to the woody seed strobili of conifers. Strobili are characterized by a central axis surrounded by spirally arranged or decussate structures that may be modified leaves or modified stems.

Plant evolution The subset of evolutionary phenomena that concern plants

Plant evolution is the subset of evolutionary phenomena that concern plants. Evolutionary phenomena are characteristics of populations that are described by averages, medians, distributions, and other statistical methods. This distinguishes plant evolution from plant development, a branch of developmental biology which concerns the changes that individuals go through in their lives. The study of plant evolution attempts to explain how the present diversity of plants arose over geologic time. It includes the study of genetic change and the consequent variation that often results in speciation, one of the most important types of radiation into taxonomic groups called clades. A description of radiation is called a phylogeny and is often represented by type of diagram called a phylogenetic tree.

Perianth

The perianth is the non-reproductive part of the flower, and structure that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla (petals). The term perianth is derived from the Greek περί, peri, meaning around, and άνθος, anthos, meaning flower, while perigonium is derived from gonos, meaning seed, i.e. sexual organs. In the mosses and liverworts (Marchantiophyta), the perianth is the sterile tubelike tissue that surrounds the female reproductive structure.

Subdivisions

The Alternifoliae Strobiloideae had five orders, arranged as follows:

Alismatales order of plants

The Alismatales (alismatids) are an order of flowering plants including about 4500 species. Plants assigned to this order are mostly tropical or aquatic. Some grow in fresh water, some in marine habitats.

Liliales order of plants

Liliales is an order of monocotyledonous flowering plants in the Angiosperm Phylogeny Group and Angiosperm Phylogeny Web system, within the lilioid monocots. This order of necessity includes the family Liliaceae. The APG III system (2009) places this order in the monocot clade. In APG III, the family Luzuriagaceae is combined with the family Alstroemeriaceae and the family Petermanniaceae is recognized. Both the Lililiales order and the Liliaceae family have had a widely disputed history, with the circumscription varying greatly from one taxonomist to another. Previous members of this order, which at one stage included most monocots with conspicuous tepals and lacking starch in the endosperm are now distributed over three orders, Liliales, Dioscoreales and Asparagales, using predominantly molecular phylogenetics. The newly delimited Liliales is monophyletic, with ten families. Well known plants from the order include Lilium (lily), tulip, the North American wildflower Trillium, and greenbrier.

Arales is a botanical name for an order of flowering plants. The name was used in the Cronquist system for an order placed in subclass Arecidae, circumscribed as (1981):

of these, the Alismatales were considered the most primitive.

while the Oppositifoliae Strobiloideae had fourteen arranged in three superorders:

Related Research Articles

Dioscoreales order of plants

The Dioscoreales are an order of monocotyledonous flowering plants in modern classification systems, such as the Angiosperm Phylogeny Group and the Angiosperm Phylogeny Web. Within the monocots Dioscoreales are grouped in the lilioid monocots where they are in a sister group relationship with the Pandanales. Of necessity the Dioscoreales contain the family Dioscoreaceae which includes the yam (Dioscorea) that is used as an important food source in many regions around the globe. Older systems tended to place all lilioid monocots with reticulate veined leaves in Dioscoreales. As currently circumscribed by phylogenetic analysis using combined morphology and molecular methods, Dioscreales contains many reticulate veined vines in Dioscoraceae, it also includes the myco-heterotrophic Burmanniaceae and the autotrophic Nartheciaceae. The order consists of three families, 22 genera and about 850 species.

Magnoliales order of plants

The Magnoliales comprise an order of flowering plants.

Monocotyledon important clade of plants

Monocotyledons, commonly referred to as monocots, are flowering plants (angiosperms) whose seeds typically contain only one embryonic leaf, or cotyledon. They constitute one of the major groups into which the flowering plants have traditionally been divided, the rest of the flowering plants having two cotyledons and therefore classified as dicotyledons, or dicots. However, molecular phylogenetic research has shown that while the monocots form a monophyletic group or clade, the dicots do not. Monocots have almost always been recognized as a group, but with various taxonomic ranks and under several different names. The APG III system of 2009 recognises a clade called "monocots" but does not assign it to a taxonomic rank.

Family is one of the eight major hierarcical taxonomic ranks in Linnaean taxonomy; it is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as being the "walnut family".

In biological classification, the order is

  1. a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family. An immediately higher rank, superorder, may be added directly above order, while suborder would be a lower rank.
  2. a taxonomic unit, a taxon, in that rank. In that case the plural is orders.
Joseph Charles Arthur American botanist

Joseph Charles Arthur was a pioneer American plant pathologist and mycologist best known for his work with the parasitic rust fungi (Pucciniales). He was a charter member of the Botanical Society of America, the Mycological Society of America, and the American Phytopathological Society. He was a recipient of the first Doctorate in Sciences awarded by Cornell University. The standard author abbreviation Arthur is used to indicate this person as the author when citing a botanical name.

Asterids major clade of plants (in APG I, II and III)

In the APG IV system (2016) for the classification of flowering plants, the name asterids denotes a clade. Common examples include the forget-me-nots, nightshades, the common sunflower, petunias, morning glory and sweet potato, coffee, lavender, lilac, olive, jasmine, honeysuckle, ash tree, teak, snapdragon, sesame, psyllium, garden sage, table herbs such as mint, basil, and rosemary, and rainforest trees such as Brazil nut.

One of the prime systems of plant taxonomy, the Engler system was devised by Adolf Engler (1844–1930), and is featured in two major taxonomic texts he authored or coauthored. His influence is reflected in the use of the terms "Engler School" and "Engler Era". Engler's starting point was that of Eichler who had been the first to use phylogenetic principles, although Engler himself did not think that his was.

Plant taxonomy is the science that finds, identifies, describes, classifies, and names plants. Thus making it one of the main branches of taxonomy.

Sympetalae subclass of plants

SympetalaeRchb. (1828), meaning “with fused petals”, is a descriptive botanical name used in the Eichler, Engler, and Wettstein systems for a group in the flowering plants. In this group the flowers have a separate calyx and corolla with the petals fused, at least at the base of the corolla, a condition known as sympetaly.

The Kubitzki system is a system of plant taxonomy devised by Klaus Kubitzki, and is the product of an ongoing survey of vascular plants, entitled The Families and Genera of Vascular Plants, and extending to 13 volumes in 2015. The survey, in the form of an encyclopedia, is important as a comprehensive, multivolume treatment of the vascular plants, with keys to and descriptions of all families and genera, mostly by specialists in those groups. The Kubitzki system served as the basis for classification in Mabberley's Plant-Book, a dictionary of the vascular plants. Mabberley states, in his Introduction on page xi of the 2008 edition, that the Kubitzki system "has remained the standard to which other literature is compared".

Lilianae superorder of plants

Lilianae is a botanical name, for a superorder of flowering plants. Such a superorder of necessity includes the type family Liliaceae. Terminations at the rank of superorder are not standardized by the International Code of Nomenclature for algae, fungi, and plants (ICN), although the suffix -anae has been proposed.

Tofieldiaceae family of plants

Tofieldiaceae is a family of flowering plants in the monocot order Alismatales. The family is divided into four genera, which together comprise 28 known species. They are small, herbaceous plants, mostly of arctic and subarctic regions, but a few extend further south, and one genus is endemic to northern South America and Florida. Tofieldia pusilla is sometimes grown as an ornamental.

Charles Edwin Bessey American botanist

Charles Edwin Bessey was an American botanist.

<i>Butomus</i> genus of plants

Butomus is the only known genus in the plant family Butomaceae, native to Europe and Asia. It is considered invasive in some parts of the United States. Two species are recognized:

Amaryllidaceae A family of flowering plants comprising members popular for horticulture and vegetable production

The Amaryllidaceae are a family of herbaceous, mainly perennial and bulbous flowering plants in the monocot order Asparagales. The family takes its name from the genus Amaryllis and is commonly known as the amaryllis family. The leaves are usually linear, and the flowers are usually bisexual and symmetrical, arranged in umbels on the stem. The petals and sepals are undifferentiated as tepals, which may be fused at the base into a floral tube. Some also display a corona. Allyl sulfide compounds produce the characteristic odour of the onion subfamily (Allioideae).

Taxonomy of Liliaceae

The taxonomy of Liliaceae has had a complex history since the first description of this flowering plant family in the mid-eighteenth century. Originally, the Liliaceae or Lily family were defined as having a "calix" (perianth) of six equal-coloured parts, six stamens, a single style, and a superior, three-chambered (trilocular) ovary turning into a capsule fruit at maturity. The taxonomic circumscription of the Liliaceae family progressively expanded until it became the largest plant family and also extremely diverse, being somewhat arbitrarily defined as all species of plants with six tepals and a superior ovary. It eventually came to encompass about 300 genera and 4,500 species, and was thus a "catch-all" and hence paraphyletic taxon. Only since the more modern taxonomic systems developed by the Angiosperm Phylogeny Group (APG) and based on phylogenetic principles, has it been possible to identify the many separate taxonomic groupings within the original family and redistribute them, leaving a relatively small core as the modern Liliaceae family, with fifteen genera and 600 species.

References

  1. Bessey, Charles E. (Feb–Apr 1915). "The Phylogenetic Taxonomy of Flowering Plants". Annals of the Missouri Botanical Garden. 2 (1/2): 109–164. doi:10.2307/2990030. JSTOR   2990030.

Sources

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