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Polystichum Scopulinum
''Polystichum scopulinum'' is a species of fern known by the common names mountain hollyfern and rock sword fern. It is native to much of western North America, and it is known from disjunct occurrences in eastern Canada as well. It grows in rocky habitat, often in full sun. It is widespread but mostly found in small populations, and is noted to be most abundant on serpentine soil Serpentine soil is an uncommon soil type produced by weathered ultramafic rock such as peridotite and its metamorphic derivatives such as serpentinite. More precisely, serpentine soil contains minerals of the serpentine subgroup, especially anti ...s. This fern produces several erect, narrowly lance-shaped leaves up to 50 centimeters in length. The leaves narrow near the bases. Each leaf is divided into many lance-shaped or oblong leaflets up to 3 centimeters long. The toothed leaflets are sometimes twisted on their axes and overlapping. ''P. scopulinum'' is probably a fertile allotetraploid with '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daniel Cady Eaton
Daniel Cady Eaton (September 12, 1834 – June 29, 1895) was an American botanist and author. After studies at the Rensselaer Institute in Troy and Russell's military school in New Haven,"Daniel Cady Eaton", ''American Journal of Science'', August 1895, p. 184. he gained his bachelor's degree at Yale College, then went on to Harvard University, where he studied with Asa Gray. He then went to Yale University's Sheffield Scientific School in 1864, where he was a botany professor and herbarium curator. Eaton is the grandson of Amos Eaton. He also worked in Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ..., contributing to the US-Mexican Boundary Survey and various geological surveys. Notable publications ''Beautiful Ferns; from Original Water-Color Drawings after Nature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Ralph Maxon
William Ralph Maxon, (February 27, 1877February 25, 1948) was an American botanist and pteridologist. He graduated from Syracuse University with a Bachelor of Philosophy, B.Ph. in biology, in 1898, and spent about one year at Columbia University doing post-graduate work on ferns with Lucien Marcus Underwood. In 1899 he accepted a position with the National Museum of Natural History, United States National Museum, which was a part of the Smithsonian Institution; he remained at the museum for his entire career. In 1899 he became an aide with the Division of Plants. He was named assistant curator in 1905, associate curator in 1914, and curator of that Division in 1937. He retired in 1946, but continued his association with the museum until his death in 1948. For the current version of this webpage, see . The later version does not indicate authorship. Alan Bain has written that, "Maxon specialized in the taxonomic study of Pteridophyta, especially those of tropical America, and was con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fern
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except the lycopods, and differ from mosses and other bryophytes by being vascular, i.e., having specialized tissues that conduct water and nutrients and in having life cycles in which the branched sporophyte is the dominant phase. Ferns have complex leaves called megaphylls, that are more complex than the microphylls of clubmosses. Most ferns are leptosporangiate ferns. They produce coiled fiddleheads that uncoil and 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 (Polypodiidae) and eusporangiate ferns, the latter group including horsetails, whisk ferns, marattioid ferns, and ophioglossoid ferns. Ferns first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disjunct Distribution
In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but considerably separated from each other geographically. The causes are varied and might demonstrate either the expansion or contraction of a species' range. Range fragmentation Also called range fragmentation, disjunct distributions may be caused by changes in the environment, such as mountain building and continental drift or rising sea levels; it may also be due to an organism expanding its range into new areas, by such means as rafting, or other animals transporting an organism to a new location (plant seeds consumed by birds and animals can be moved to new locations during bird or animal migrations, and those seeds can be deposited in new locations in fecal matter). Other conditions that can produce disjunct distributions include: flooding, or changes in wind, stream, and current flows, plus others such as anthropogenic introduction of alien introduced species either acciden ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpentine Soil
Serpentine soil is an uncommon soil type produced by weathered ultramafic rock such as peridotite and its metamorphic derivatives such as serpentinite. More precisely, serpentine soil contains minerals of the serpentine subgroup, especially antigorite, lizardite, and chrysotile or white asbestos, all of which are commonly found in ultramafic rocks. The term "serpentine" is commonly used to refer to both the soil type and the mineral group which forms its parent materials. Serpentine soils exhibit distinct chemical and physical properties and are generally regarded as poor soils for agriculture. The soil is often reddish, brown, or gray in color due to its high iron and low organic content. Geologically, areas with serpentine bedrock are characteristically steep, rocky, and vulnerable to erosion, which causes many serpentine soils to be rather shallow. The shallow soils and sparse vegetation lead to elevated soil temperatures and dry conditions. Due to their ultramafic origin, ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polystichum Munitum
''Polystichum munitum'', the western swordfern, is an evergreen perennial fern native to western North America, where it is one of the most abundant ferns in forested areas. It occurs along the Pacific coast from southeastern Alaska to southern California, and also inland east to southeastern British Columbia, northern Idaho and western Montana, with disjunctive populations in northern British Columbia, Canada; the Black Hills in South Dakota, United States; and Guadalupe Island off of Baja California, Mexico. Western swordfern is known to have locally naturalized in parts of Great Britain and Ireland. Description The dark green fronds of this fern grow tall, in a tight clump spreading out radially from a round base. They are single-pinnate, with the pinnae alternating on the stalk. Each pinna is long, with a small upward-pointing lobe (a sword hilt, hence the name) at the base, and the edges are serrated with bristly tips. Individual fronds live for 1.5 to 2.5 years and remai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
