Ploidy is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair, which chromosomes naturally exist as. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present : monoploid, diploid, triploid, tetraploid, pentaploid, hexaploid, heptaploid or septaploid, etc. The generic term polyploid is often used to describe cells with three or more sets of chromosomes.
Polyploidy is a condition in which the cells of an organism have more than one pair of (homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two complete sets of chromosomes, one from each of two parents; each set contains the same number of chromosomes, and the chromosomes are joined in pairs of homologous chromosomes. However, some organisms are polyploid. Polyploidy is especially common in plants. Most eukaryotes have diploid somatic cells, but produce haploid gametes by meiosis. A monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Males of bees and other Hymenoptera, for example, are monoploid. Unlike animals, plants and multicellular algae have life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis; the sporophyte generation is diploid and produces spores by meiosis.
Acorus is a genus of monocot flowering plants. This genus was once placed within the family Araceae (aroids), but more recent classifications place it in its own family Acoraceae and order Acorales, of which it is the sole genus of the oldest surviving line of monocots. Some older studies indicated that it was placed in a lineage, that also includes aroids (Araceae), Tofieldiaceae, and several families of aquatic monocots. However, modern phylogenetic studies demonstrate that Acorus is sister to all other monocots. Common names include calamus and sweet flag.
Acorus calamus is a species of flowering plant with psychoactive chemicals. It is a tall wetland monocot of the family Acoraceae, in the genus Acorus. Although used in traditional medicine over centuries to treat digestive disorders and pain, there is no clinical evidence for its safety or efficacy – and ingested calamus may be toxic – leading to its commercial ban in the United States.
The large skipper is a butterfly of the family Hesperiidae.
Arisaema triphyllum, the Jack-in-the-pulpit, is a species of flowering plant in the arum family Araceae. It is a member of the Arisaema triphyllum complex, a group of four or five closely related taxa in eastern North America. The specific name triphyllum means "three-leaved", a characteristic feature of the species, which is also referred to as Indian turnip, bog onion, and brown dragon.
Aegilops is a genus of Eurasian and North American plants in the grass family, Poaceae. They are known generally as goatgrasses. Some species are known as invasive weeds in parts of North America.
Lamium galeobdolon, the yellow archangel, is a species of flowering plant in the mint family Lamiaceae. It is native to Europe and western Asia but it is widely introduced in North America and elsewhere. It is the only species in the genus Lamium with yellow flowers. Another common name for this species is golden dead-nettle. In New Zealand, it is called the aluminium plant or artillery plant. The common names archangel and dead-nettle have been in use for hundreds of years, dating back to at least the 16th century.
During 10,000 years of cultivation, numerous forms of wheat, many of them hybrids, have developed under a combination of artificial and natural selection. This diversity has led to much confusion in the naming of wheats. Genetic and morphological characteristics of wheat influence its classification; many common and botanical names of wheat are in current use.
Dactylis glomerata is a species of flowering plant in the grass family Poaceae, known as cock's-foot, also colloquially as orchard grass, or cat grass (due to its popularity for use with domestic cats). It is a cool-season perennial C3 tufted grass native throughout most of Europe, temperate Asia, and northern Africa.
Arrhenatherum elatius is a species of flowering plant in the grass family Poaceae, commonly known as false oat-grass, and also bulbous oat grass, tall oat-grass, tall meadow oat, onion couch and tuber oat-grass. It is native throughout Europe, and also western and southwestern Asia, and northwestern Africa. This tufted grass is sometimes used as an ornamental grass and is sometimes marketed as "cat grass".
Hordeum murinum is a species of flowering plant in the grass family Poaceae, commonly known as wall barley or false barley. It is a close relative of cultivated barley.
Asplenium trichomanes, the maidenhair spleenwort, is a small fern in the spleenwort genus Asplenium. It is a widespread and common species, occurring almost worldwide in a variety of rocky habitats. It is a variable fern with several subspecies.
Asplenium septentrionale is a species of fern known by the common names northern spleenwort and forked spleenwort. It is native to Europe, Asia and western North America, where it grows on rocks. Its long, slender leaves give it a distinctive appearance. Three subspecies exist, corresponding to a tetraploid and a diploid cytotype and their triploid hybrid.
Aeluropus is a genus of Eurasian and African plants in the grass family, found primarily in desert regions.
Chaetobromus is a genus of African plants in the grass family.
Solidago altissima, the tall goldenrod or late goldenrod, is a North American species of goldenrod in the family Asteraceae which is widespread across much of Canada, the United States, and northern Mexico. It is common in much of its range and fairly tolerant of landscapes which have been disturbed by humans. It has become naturalized in many parts of the world.
Polypodium appalachianum is a fern species native to eastern North America. Sometimes called the Appalachian polypody or Appalachian rockcap fern, it is very similar in appearance to Polypodium virginianum. For years, P. virginianum—long considered a variety of the British Polypodium vulgare—was recognized as having cryptic races, with diploid, triploid, and tetraploid representatives. Since the triploid specimens bore abortive spores, it was apparently the hybrid between the diploid and tetraploid groups. In 1991, it was resolved that the type of P. virginianum was the tetraploid series, and that it is an allotetraploid species of hybrid origin, with the diploid species as one parent. The diploid species was then named P. appalachianum. The other parent of P. virginianum was found to be Polypodium sibiricum. The tetraploid of hybrid derivation tolerates warmer climates than either parent.
Glyphipterix achlyoessa, commonly known as the cocksfoot stem borer, is a species of moth in the family Glyphipterigidae. It is endemic to New Zealand and can be found throughout the country. This species inhabits meadows and open grasslands. The larvae are hosted by species in the genus Juncus as well as by the species Dactylis glomerata. Adult moths are commonly on the wing from October to December.
Alloteropsis semialata, known commonly as black seed grass, cockatoo grass, donkersaad gras, swartsaadgras, tweevingergras, and isi quinti, is a perennial grass distributed across much of tropical and subtropical Africa, Asia and Australia, as well as Papuasia and Madagascar. The genus name Allopteropsis comes from the Greek words "allotrios", meaning "belonging to another", and "opsis", meaning appearance. The specific epithet semialata comes from the Latin "semi" (half) and "ala" (wing), referring to the winged margins of the upper glume.
