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Crataegus Mollis
''Crataegus mollis'', known as downy hawthorn or red hawthorn, is a species of plant that occurs in eastern North America from southeastern North Dakota east to Nova Scotia and southwest to eastern Texas. The range of this species is from southern Ontario and Michigan to eastern North Dakota and southward to Denison, Texas, and Arizona. This tree inhabits wooded bottomlands, the prairie border, and the midwest savanna understorey. Description This tree grows to high with a dense crown of thorny branches and an ash-grey trunk. The leaves are in length and often drop in late summer due to defoliation by leaf diseases. The tree seems to suffer little from the early loss of its leaves. Among the earliest in the genus to bloom, downy hawthorn also has earliest ripening fruit, which decorate the defoliated tree in late summer and early fall. The large brightly colored edible fruit of the species ripen from the middle of August to early in September. It is closely related to ''Crataeg ...
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John Torrey
John Torrey (August 15, 1796 – March 10, 1873) was an American botany, botanist, chemist, and physician. Throughout much of his career, he was a teacher of chemistry, often at multiple universities, while he also pursued botanical work, focusing on the flora of North America. His most renowned works include studies of the New York flora, the Mexican Boundary, the Pacific railroad surveys, and the uncompleted ''Flora of North America''. Biography Torrey was born in New York City, the second child of Capt. William and Margaret (née Nichols) Torrey.Robbins, C. C. (1968). John Torrey (1796–1873), His Life & Times. ''Bulletin of the Torrey Botanical Club''. Vol. 95, No. Nov. 6–Dec. 1968, 515–645. Torrey Botanical Club, New York. He showed a fondness for mechanics, and at one time planned to become a machinist. When he was 15 or 16, his father received an appointment to the state prison at Greenwich Village, New York, where he was tutored by Amos Eaton, then a pri ...
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Defoliant
A defoliant is any herbicidal chemical sprayed or dusted on plants to cause their leaves to fall off. Defoliants are widely used for the selective removal of weeds in managing croplands and lawns. Worldwide use of defoliants, along with the development of other herbicides and pesticides, allowed for the Green Revolution, an increase in agricultural production in mid-20th century. Defoliants have also been used in warfare as a means to deprive an enemy of food crops and/or hiding cover, most notably by the United Kingdom during the Malayan Emergency and the United States in the Vietnam War. Defoliants were also used by Indonesian forces in various internal security operations. Use and application A primary application of defoliants is the selective killing of plants. Two of the oldest chemical herbicides used as defoliants are 2,4-Dichlorophenoxyacetic acid (2,4-D) and 2,4,5-Trichlorophenoxyacetic acid (2,4,5-T). 2,4-D and 2,4,5-T are absorbed by broad-leafed plants, killi ...
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Crataegus
''Crataegus'' (), commonly called hawthorn, quickthorn, thornapple, Voss, E. G. 1985. ''Michigan Flora: A guide to the identification and occurrence of the native and naturalized seed-plants of the state. Part II: Dicots (Saururaceae–Cornaceae)''. Cranbrook Institute of Science and University of Michigan Herbarium, Ann Arbor, Michigan. May-tree,Graves, Robert. ''The White Goddess: A Historical Grammar of Poetic Myth'', 1948, amended and enlarged 1966, New York: Farrar, Straus and Giroux. whitethorn, Mayflower, or hawberry, is a genus of several hundred species of shrubs and trees in the family Rosaceae, native to temperate regions of the Northern Hemisphere in Europe, Asia, North Africa, and North America. The name "hawthorn" was originally applied to the species native to northern Europe, especially the common hawthorn ''C. monogyna'', and the unmodified name is often so used in Britain and Ireland. The name is now also applied to the entire genus and to the related Asian ...
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Flora Of Canada
The flora of Canada is quite diverse, due to the wide range of ecoregions and environmental conditions present in Canada. From the warm, temperate broadleaf forests of southern Ontario to the frigid Arctic plains of Northern Canada, from the wet temperate rainforests of the west coast to the arid deserts, badlands and tundra plains, the biodiversity of Canada's plants is extensive. According to environment Canada the nation of Canada hosts approximately 17,000 identified species of trees, flowers, herbs, ferns, mosses and other flora. About 4,100 species of vascular plants are native to Canada, and about 1,200 additional non-native species are recorded as established outside cultivation there. Lists of all plants * List of Canadian plants by family : A , B , C , D , E , F , G , H , I J K , L , M , N , O , P Q , R , S , T , U V W , X Y Z * List of Canadian plants by genus : A , B , C , D , E , F , G , H , I J K , L , M ...
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Fire Blight
Fire blight, also written fireblight, is a contagious disease affecting apples, pears, and some other members of the family Rosaceae. It is a serious concern to apple and pear producers. Under optimal conditions, it can destroy an entire orchard in a single growing season. The causal pathogen is ''Erwinia amylovora'', a Gram-negative bacterium in the genus ''Erwinia'', order Enterobacterales. It is a short rod with rounded ends and many peritrichous flagellae. Pears are the most susceptible, but apples, loquat, crabapples, quinces, hawthorn, cotoneaster, ''Pyracantha'', raspberry and some other rosaceous plants are also vulnerable. The disease is believed to be indigenous to North America, from where it spread to most of the rest of the world. Fire blight is not believed to be present in Australia though it might possibly exist there. It has been a major reason for a long-standing embargo on the importation of New Zealand apples to Australia. Japan was likewise believed to b ...
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Gypsy Moth
''Lymantria dispar'', also known as the gypsy moth or the spongy moth, is a species of moth in the family Erebidae. ''Lymantria dispar'' is subdivided into several subspecies, with subspecies such as ''L. d. dispar'' and ''L. d. japonica'' being clearly identifiable without ambiguity. ''Lymantria dispar'' has been introduced to several continents and is now found in Europe, Africa, Asia, North America and South America. The polyphagous larvae live on a variety of deciduous and coniferous trees and can cause severe damage in years of mass reproduction. Due to these features, ''Lymantria dispar'' is listed among the world's 100 worst invasive alien species. Etymology The name “gypsy moth” does not have conclusive origins, however it has been in use since 1908. Moths of the subfamily Lymantriinae are commonly called tussock moths due to the tussock-like tufts of hair on the caterpillars.The Gypsy Moth: Research Toward Integrated Pest Management, United States Department o ...
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Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanism for the union of sperm with eggs. Flowers may facilitate outcrossing (fusion of sperm and eggs from different individuals in a population) resulting from cross-pollination or allow selfing (fusion of sperm and egg from the same flower) when self-pollination occurs. There are two types of pollination: self-pollination and cross-pollination. Self-pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant. Cross-pollination is when pollen is transferred from the anther of one flower to the stigma of another flower on a different individual of the same species. Self-pollination happens in flowers where the stamen and carpel mature at the same time, and are positi ...
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Stamen
The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament and an anther which contains ''sporangium, microsporangia''. Most commonly anthers are two-lobed and are attached to the filament either at the base or in the middle area of the anther. The sterile tissue between the lobes is called the connective, an extension of the filament containing conducting strands. It can be seen as an extension on the dorsal side of the anther. A pollen grain develops from a microspore in the microsporangium and contains the male gametophyte. The stamens in a flower are collectively called the androecium. The androecium can consist of as few as one-half stamen (i.e. a single locule) as in ''Canna (plant), Canna'' species or as many as 3,482 stamens which have been counted in the saguaro (''Carnegiea gigantea'' ...
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Crataegus Submollis
''Crataegus submollis'', known as the northern downy hawthorn, northern red haw, Quebec hawthorn, or hairy cockspurthorn, is a species of hawthorn Hawthorn or Hawthorns may refer to: Plants * '' Crataegus'' (hawthorn), a large genus of shrubs and trees in the family Rosaceae * ''Rhaphiolepis'' (hawthorn), a genus of about 15 species of evergreen shrubs and small trees in the family Rosace ... that grows to about 7 m in height and typically carries large crops of red fruit. This species is closely related to '' C. mollis'', but the two species have separate native ranges. Amongst other differences between these two species, ''C. mollis'' has approximately 20 stamens, whereas ''C. submollis'' has approximately 10 stamens per flower. ''Crataegus submollis'' is native to north-eastern North America, and has been introduced in Europe. The thorns are usually numerous and up to 7 cm in length. Images Crataegus_submollis_flowers.jpg, Flowers References submollis ...
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Leaf
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, flower, and fruit collectively form the shoot system. In most leaves, the primary photosynthetic tissue is the palisade mesophyll and is located on the upper side of the blade or lamina of the leaf but in some species, including the mature foliage of ''Eucalyptus'', palisade mesophyll is present on both sides and the leaves are said to be isobilateral. Most leaves are flattened and have distinct upper (adaxial) and lower ( abaxial) surfaces that differ in color, hairiness, the number of stomata (pores that intake and output gases), the amount and structure of epicuticular wax and other features. Leaves are mostly green in color due to the presence of a compound called chlorophyll that is essential for photosynthesis as it absorbs light ...
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Asa Gray
Asa Gray (November 18, 1810 – January 30, 1888) is considered the most important American botanist of the 19th century. His ''Darwiniana'' was considered an important explanation of how religion and science were not necessarily mutually exclusive. Gray was adamant that a genetic connection must exist between all members of a species. He was also strongly opposed to the ideas of hybridization within one generation and special creation in the sense of its not allowing for evolution. He was a strong supporter of Darwin, although Gray's theistic evolution was guided by a Creator. As a professor of botany at Harvard University for several decades, Gray regularly visited, and corresponded with, many of the leading natural scientists of the era, including Charles Darwin, who held great regard for him. Gray made several trips to Europe to collaborate with leading European scientists of the era, as well as trips to the southern and western United States. He also built an extensive ne ...
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