Ophioglossum engelmannii known as the limestone adder's-tongue, is species of fern native to the Western Hemisphere. It is widespread and native to the United States and Central America, its primary natural habitat is dry glades in calcareous areas. It is a small species that dies back in the summer. A second growth of leaves is sometimes produced with the fall rains
A fern is a member of a group of vascular plants that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e. having specialized tissues that conduct water and nutrients and in having life cycles in which the sporophyte is the dominant phase. Like other vascular plants, ferns have complex leaves called megaphylls, that are more complex than the microphylls of clubmosses. Most ferns are leptosporangiate ferns, sometimes referred to as true ferns, they produce coiled fiddleheads that expand into fronds. The group includes about 10,560 known extant species. Ferns are defined here in the broad sense, being all of the Polypodiopsida, comprising both the leptosporangiate and eusporangiate ferns, the latter itself comprising ferns other than those denominated true ferns, including horsetails or scouring rushes, whisk ferns, marattioid ferns, ophioglossoid ferns. Ferns first appear in the fossil record about 360 million years ago in the late Devonian period, but many of the current families and species did not appear until 145 million years ago in the early Cretaceous, after flowering plants came to dominate many environments.
The fern Osmunda claytoniana is a paramount example of evolutionary stasis. Ferns are not of major economic importance, but some are used for food, medicine, as biofertilizer, as ornamental plants and for remediating contaminated soil, they have been the subject of research for their ability to remove some chemical pollutants from the atmosphere. Some fern species, such as bracken and water fern are significant weeds world wide; some fern genera, such as Azolla can fix nitrogen and make a significant input to the nitrogen nutrition of rice paddies. They play certain roles in mythology and art. Like the sporophytes of seed plants, those of ferns consist of stems and roots. Stems: Fern stems are referred to as rhizomes though they grow underground only in some of the species. Epiphytic species and many of the terrestrial ones have above-ground creeping stolons, many groups have above-ground erect semi-woody trunks; these can reach up to 20 meters tall in a few species. Leaf: The green, photosynthetic part of the plant is technically a megaphyll and in ferns, it is referred to as a frond.
New leaves expand by the unrolling of a tight spiral called a crozier or fiddlehead fern. This uncurling of the leaf is termed circinate vernation. Leaves are divided into a sporophyll. A trophophyll frond is a vegetative leaf analogous to the typical green leaves of seed plants that does not produce spores, instead only producing sugars by photosynthesis. A sporophyll frond is a fertile leaf that produces spores borne in sporangia that are clustered to form sori. In most ferns, fertile leaves are morphologically similar to the sterile ones, they photosynthesize in the same way. In some groups, the fertile leaves are much narrower than the sterile leaves, may have no green tissue at all; the anatomy of fern leaves can either be simple or divided. In tree ferns, the main stalk that connects the leaf to the stem has multiple leaflets; the leafy structures that grow from the stipe are known as pinnae and are again divided into smaller pinnules. Roots: The underground non-photosynthetic structures that take up water and nutrients from soil.
They are always fibrous and structurally are similar to the roots of seed plants. Like all other vascular plants, the diploid sporophyte is the dominant phase or generation in the life cycle; the gametophytes of ferns, are different from those of seed plants. They are free-living and resemble liverworts, whereas those of seed plants develop within the spore wall and are dependent on the parent sporophyte for their nutrition. A fern gametophyte consists of: Prothallus: A green, photosynthetic structure, one cell thick heart or kidney shaped, 3–10 mm long and 2–8 mm broad; the prothallus produces gametes by means of: Antheridia: Small spherical structures that produce flagellate sperm. Archegonia: A flask-shaped structure that produces a single egg at the bottom, reached by the sperm by swimming down the neck. Rhizoids: root-like structures that consist of single elongated cells, that absorb water and mineral salts over the whole structure. Rhizoids anchor the prothallus to the soil. Ferns first appear in the fossil record in the early Carboniferous period.
By the Triassic, the first evidence of ferns related to several modern families appeared. The great fern radiation occurred in the late Cretaceous, when many modern families of ferns first appeared. Ferns were traditionally classified in the class Filices, in a Division of the Plant Kingdom named Pteridophyta or Filicophyta. Pteridophyta is no longer recognised as a valid taxon; the ferns are referred to as Polypodiophyta or, when treated as a subdivision of Tracheophyta, although this name sometimes only refers to leptosporangiate ferns. Traditionally, all of the spore producing vascular plants were informally denominated the pteridophytes, rendering the term synonymous with ferns and fern allies; this can be confusing because members of the division Pteridophyta were denominated pteridophytes. Traditionally, three discrete groups have be
Ophioglossum pusillum is a species of fern in the family Ophioglossaceae known by the common name northern adder's tongue. It is native to northern North America, where it is widespread in moist areas such as marshes and meadows, it is found from northern California through Alaska on the west, from central Appalachia through the northern Great Plains and the Great Lakes regions, across the Northeastern United States and Eastern Canada. Ophioglossum pusillum is a small, fleshy perennial plant growing from a caudex no more than 3 centimeters wide, it produces one leaf per year. The leaf is divided into a thin, pale green blade-shaped part, sterile, a fertile stalk lined with two rows of sporangia. USDA Plants Profile of Ophioglossum pusillum Jepson Manual Treatment for Ophioglossum pusillum Flora of North America: Ophioglossum pusillum Ophioglossum pusillum — U. C. Photo gallery
Flora of China
The flora of China is diverse. More than 30,000 plant species are native to China, representing nearly one-eighth of the world's total plant species, including thousands found nowhere else on Earth. China contains a variety of forest types. Both northeast and northwest reaches contain mountains and cold coniferous forests, supporting animal species which include moose and Asiatic black bear, along with some 120 types of birds. Moist conifer forests can have thickets of bamboo as an understorey, replaced by rhododendrons in higher montane stands of juniper and yew. Subtropical forests, which dominate central and southern China, support an astounding 146,000 species of flora. Tropical rainforest and seasonal rainforests, though confined to Yunnan and Hainan Island, contain a quarter of all the plant and animal species found in China; the flora of China has an online database which gives both its taxonomy. Media related to Flora of China at Wikimedia Commons eflora: Flora of China
In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. Such a taxon is said to exhibit cosmopolitism; the opposite extreme is endemism. The term pandemism is in use, but not all authors are consistent in the sense in which they use the term; this means near cosmopolitanism, but with major gaps in the distribution, complete absence from Australia. Terminology varies, there is some debate whether the true opposite of endemism is pandemism or cosmopolitism; the term "cosmopolitan distribution" should not be taken because it is applied loosely in various contexts. The intention is not to include polar regions, extreme altitudes, deserts, or small, isolated islands. For example, the housefly is nearly as cosmopolitan as any animal species, but it is neither oceanic nor polar in its distribution; the term "cosmopolitan weed" implies no more than that the plant in question occurs on all continents except Antarctica.
Another concept in biogeography is that of oceanic endemism. Although there is a temptation to regard the World Ocean as a medium without biological boundaries, this is far from reality. For example, temperature gradients prevent free migration of tropical species between the Atlantic and Indian-plus-Pacific oceans though there is open passage past continental masses such as the Americas and Africa/Eurasia. Again, as far as many species are concerned, the Southern Ocean and the Northern marine regions are isolated from each other by the intolerable temperatures of the tropical regions. In the light of such considerations, it is no surprise to find that endemism and cosmopolitanism are quite as marked in the oceans as on land. Another aspect of cosmopolitanism is that of ecological limitations. A species, cosmopolitan because it occurs in all oceans might in fact occupy only littoral zones, or only particular ranges of depths, or only estuaries, for example. Analogously, terrestrial species might be present only in forests, or mountainous regions, or sandy arid regions or the like.
Such distributions might be patchy, or extended. Factors of such a nature are taken for granted, so they are mentioned explicitly in mentioning cosmopolitan distributions. Cosmopolitanism of a particular species or variety should not be confused with cosmopolitanism of higher taxa. For example, the family Myrmeleontidae is cosmopolitan in the sense that every continent except Antarctica is home to some indigenous species within the Myrmeleontidae, but nonetheless no one species, nor genus, of the Myrmeleontidae is cosmopolitan. Conversely as a result of human introduction of unnatural apiculture to the New World, Apis mellifera is the only cosmopolitan member of its family. Where a cosmopolitan population is recognised as a single species, such as indeed Apis mellifera, there will be variation between regional sub-populations; such variation is at the level of subspecies, varieties or morphs, whereas some variation is too slight or inconsistent for formal recognition. For an example of subspecific variation, consider the so-called "African killer bee", the subspecies Apis mellifera scutellata, the Cape bee, the subspecies Apis mellifera capensis.
Other cosmopolitan species, such as the osprey and house sparrow, present similar examples, but in yet other species there are less familiar complications: some migratory birds such as the Arctic tern occur from the Arctic to the Southern Ocean, but at any one season of the year they are to be in passage or concentrated at only one end of the range. Some such species breed only at one end of the range. Seen purely as an aspect of cosmopolitanism, such distributions could be seen as temporal, seasonal variations. Other complications of cosmopolitanism on a planet too large for local populations to interbreed with each other, lead to genetic effects such as ring species, for example in the Larus gulls, they lead to the formation of clines such as in Drosophila. Cosmopolitan distributions can be observed both in extinct and extant species. For example, Lystrosaurus was cosmopolitan in the Early Triassic after a mass extinction. In the modern world, the killer whale has a cosmopolitan distribution, extending over most of the Earth's oceans.
The wasp Copidosoma floridanum is another example. Other examples include humans, dogs, the foliose lichen Parmelia sulcata, the mollusc genus Mytilus; the term can apply to some diseases. It may result from a broad range of environmental tolerances or from rapid dispersal compared to the time needed for evolution. Ecoregion Gondwanan distribution Holarctic Pantropical The dictionary definition of cosmopolitan at Wiktionary
Ophioglossales are a small group of pteridophyte plants. Traditionally they were included in the ferns as a family and as the order Ophioglossales. In some classifications this group is placed in a separate division, the Ophioglossophyta, but recent molecular systematic studies have shown the Ophioglossales to be related to the Psilotales, both are placed in the class Ophioglossidae. In the molecular phylogenetic classification of Smith et al. in 2006, Ophioglossales, in its present circumscription, was placed with the order Psilotales in the class Psilotopsida. The linear sequence of Christenhusz et al. intended for compatibility with the classification of Chase and Reveal which placed all land plants in Equisetopsida, made it a member of subclass Ophioglossidae, equivalent to Smith's Psilotopsida. The placement of Ophioglossales in subclass Ophioglossidae has subsequently been followed in the classifications of Christenhusz and Chase and PPG I. Older treatments have recognized segregate families within Ophioglossales such as Botrychiaceae for the moonworts and grape ferns and Helminthostachyaceae for Helminthostachys, but all modern treatments combine all members of the order into the single family Ophioglossaceae.
The plants have short-lived spores formed in sporangia lacking an annulus, borne on a stalk that splits from the leaf blade. Many species only send up one leaf-blade per year. A few species send up the fertile spikes only, without any conventional leaf-blade; the gametophytes are subterranean. The spores will not germinate if exposed to sunlight, the gametophyte can live some two decades without forming a sporophyte; the genus Ophioglossum has the highest chromosome counts of any known plant. The record holder is Ophioglossum reticulatum, with about 630 pairs of chromosomes. Ophioglossophyta images
Carl Linnaeus known after his ennoblement as Carl von Linné, was a Swedish botanist and zoologist who formalised binomial nomenclature, the modern system of naming organisms. He is known as the "father of modern taxonomy". Many of his writings were in Latin, his name is rendered in Latin as Carolus Linnæus. Linnaeus was born in the countryside of Småland in southern Sweden, he received most of his higher education at Uppsala University and began giving lectures in botany there in 1730. He lived abroad between 1735 and 1738, where he studied and published the first edition of his Systema Naturae in the Netherlands, he returned to Sweden where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on several journeys through Sweden to find and classify plants and animals. In the 1750s and 1760s, he continued to collect and classify animals and minerals, while publishing several volumes, he was one of the most acclaimed scientists in Europe at the time of his death. Philosopher Jean-Jacques Rousseau sent him the message: "Tell him I know no greater man on earth."
Johann Wolfgang von Goethe wrote: "With the exception of Shakespeare and Spinoza, I know no one among the no longer living who has influenced me more strongly." Swedish author August Strindberg wrote: "Linnaeus was in reality a poet who happened to become a naturalist." Linnaeus has been called Princeps botanicorum and "The Pliny of the North". He is considered as one of the founders of modern ecology. In botany and zoology, the abbreviation L. is used to indicate Linnaeus as the authority for a species' name. In older publications, the abbreviation "Linn." is found. Linnaeus's remains comprise the type specimen for the species Homo sapiens following the International Code of Zoological Nomenclature, since the sole specimen that he is known to have examined was himself. Linnaeus was born in the village of Råshult in Småland, Sweden, on 23 May 1707, he was the first child of Christina Brodersonia. His siblings were Anna Maria Linnæa, Sofia Juliana Linnæa, Samuel Linnæus, Emerentia Linnæa, his father taught him Latin as a small child.
One of a long line of peasants and priests, Nils was an amateur botanist, a Lutheran minister, the curate of the small village of Stenbrohult in Småland. Christina was the daughter of the rector of Samuel Brodersonius. A year after Linnaeus's birth, his grandfather Samuel Brodersonius died, his father Nils became the rector of Stenbrohult; the family moved into the rectory from the curate's house. In his early years, Linnaeus seemed to have a liking for plants, flowers in particular. Whenever he was upset, he was given a flower, which calmed him. Nils spent much time in his garden and showed flowers to Linnaeus and told him their names. Soon Linnaeus was given his own patch of earth. Carl's father was the first in his ancestry to adopt a permanent surname. Before that, ancestors had used the patronymic naming system of Scandinavian countries: his father was named Ingemarsson after his father Ingemar Bengtsson; when Nils was admitted to the University of Lund, he had to take on a family name. He adopted the Latinate name Linnæus after a giant linden tree, lind in Swedish, that grew on the family homestead.
This name was spelled with the æ ligature. When Carl was born, he was named Carl Linnæus, with his father's family name; the son always spelled it with the æ ligature, both in handwritten documents and in publications. Carl's patronymic would have been Nilsson, as in Carl Nilsson Linnæus. Linnaeus's father began teaching him basic Latin and geography at an early age; when Linnaeus was seven, Nils decided to hire a tutor for him. The parents picked a son of a local yeoman. Linnaeus did not like him, writing in his autobiography that Telander "was better calculated to extinguish a child's talents than develop them". Two years after his tutoring had begun, he was sent to the Lower Grammar School at Växjö in 1717. Linnaeus studied going to the countryside to look for plants, he reached the last year of the Lower School when he was fifteen, taught by the headmaster, Daniel Lannerus, interested in botany. Lannerus gave him the run of his garden, he introduced him to Johan Rothman, the state doctor of Småland and a teacher at Katedralskolan in Växjö.
A botanist, Rothman broadened Linnaeus's interest in botany and helped him develop an interest in medicine. By the age of 17, Linnaeus had become well acquainted with the existing botanical literature, he remarks in his journal that he "read day and night, knowing like the back of my hand, Arvidh Månsson's Rydaholm Book of Herbs, Tillandz's Flora Åboensis, Palmberg's Serta Florea Suecana, Bromelii Chloros Gothica and Rudbeckii Hortus Upsaliensis...."Linnaeus entered the Växjö Katedralskola in 1724, where he studied Greek, Hebrew and mathematics, a curriculum designed for boys preparing for the priesthood. In the last year at the gymnasium, Linnaeus's father visited to ask the professors how his son's studies were progressing. Rothman believed otherwise; the doctor offered to have Linnaeus live with his family in Växjö and to teach him physiology and botany. Nils accepted this offer. Rothman showed Linnaeus that botany was a serious sub