|
Stegophora Ulmea
''Stegophora ulmea'' is a foliar disease of elms commonly known as black spot of elm, twig blight, and elm leaf scab. It is characterized by yellow spots that become black spots on the leaves. The pathogen is an ascomycete fungus native to North America. ''Stegophora ulmea'' is its teleomorph name. It has two anamorph names, Gloeosporium ''ulmicolom'' referring to the macroconidia stage and ''Cylindrosporella ulmea'' referring to the microconidia stage. This pathogen was formerly known as ''Gnomonia ulmea''''.'' Hosts and symptoms ''Stegophora ulmea'' infects all ''Ulmus'' species and Japanese zelkova. It is most virulent on American white elm, '' Ulmus Americana''''.'' Other elms it is known to infect include: * ''Ulmus alata'' (winged elm) * '' Ulmus carpinifolia'' (European field elm) * '' Ulmus crassifolia'' (cedar elm) * '' Ulmus glabra'' (Wych elm) * '' Ulmus hollandica'' (Dutch elm) * ''Ulmus japonica'' (Japanese elm) * ''Ulmus laciniata'' * ''Ulmus laevis'' (Europea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungi
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from the other eukaryotic kingdoms, which by one traditional classification include Plantae, Animalia, Protozoa, and Chromista. A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the ''Eumycota'' (''t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulmus Japonica
''Ulmus davidiana'' var. ''japonica'', the Japanese elm, is one of the larger and more graceful Asiatic elms, endemic to much of continental northeast Asia and Japan, where it grows in swamp forest on young alluvial soils, although much of this habitat has now been lost to intensive rice cultivation.Makita, H., Miyagi, T., Miura, O., and Kikuchi, T. (1979). A study of an alder forest and an elm forest with special reference to their geomorphological conditions in a small tributary basin. In: Vegetation und Lansdschaft Japans. ''Bull: Yokohama Phytosoc. Soc. Japan'' 16, 1979 Description The size and shape of the Japanese elm is extremely variable, ranging from short and bearing a densely branched broad crown similar to the Wych elm to tall, single-stemmed, with narrow crown similar to the English elm. Augustine Henry described one of the latter outside Iwamigawa, Hokkaido, railway station as being 34 m tall, with a clean stem to a height of approximately 15 m.Elwes, H. J. & ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perithecial
An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are most commonly bowl-shaped (apothecia) but may take on a spherical or flask-like form that has a pore opening to release spores (perithecia) or no opening (cleistothecia). Classification The ascocarp is classified according to its placement (in ways not fundamental to the basic taxonomy). It is called ''epigeous'' if it grows above ground, as with the morels, while underground ascocarps, such as truffles, are termed ''hypogeous''. The structure enclosing the hymenium is divided into the types described below (apothecium, cleistothecium, etc.) and this character ''is'' important for the taxonomic classification of the fungus. Apothecia can be relatively large and fleshy, whereas the others are microscopic—about the size of flecks of g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascospore
An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or species can occur in numbers of one (e.g. ''Monosporascus cannonballus''), two, four, or multiples of four. In a few cases, the ascospores can bud off conidia that may fill the asci (e.g. ''Tympanis'') with hundreds of conidia, or the ascospores may fragment, e.g. some ''Cordyceps'', also filling the asci with smaller cells. Ascospores are nonmotile, usually single celled, but not infrequently may be coenocytic (lacking a septum), and in some cases coenocytic in multiple planes. Mitotic divisions within the developing spores populate each resulting cell in septate ascospores with nuclei. The term ocular chamber, or oculus, refers to the epiplasm (the portion of cytoplasm not used in ascospore formation) that is surrounded by the "bourrelet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Necrosis
Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated digestion of cell components. In contrast, apoptosis is a naturally occurring programmed and targeted cause of cellular death. While apoptosis often provides beneficial effects to the organism, necrosis is almost always detrimental and can be fatal. Cellular death due to necrosis does not follow the apoptotic signal transduction pathway, but rather various receptors are activated and result in the loss of cell membrane integrity and an uncontrolled release of products of cell death into the extracellular space. This initiates in the surrounding tissue an inflammatory response, which attracts leukocytes and nearby phagocytes which eliminate the dead cells by phagocytosis. However, microbial damaging substances released by leukocytes would crea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorosis
In botany, chlorosis is a condition in which leaves produce insufficient chlorophyll. As chlorophyll is responsible for the green color of leaves, chlorotic leaves are pale, yellow, or yellow-white. The affected plant has little or no ability to manufacture carbohydrates through photosynthesis and may die unless the cause of its chlorophyll insufficiency is treated and this may lead to a plant diseases called rusts, although some chlorotic plants, such as the albino ''Arabidopsis thaliana'' mutant ''ppi2'', are viable if supplied with exogenous sucrose. The word ''chlorosis'' is derived from the Greek ''khloros'' meaning "greenish-yellow", "pale green", "pale", "pallid", or "fresh". In viticulture, the most common symptom of poor nutrition in grapevines is the yellowing of grape leaves caused by chlorosis and the subsequent loss of chlorophyll. This is often seen in vineyard soils that are high in limestone such as the Italian wine region of Barolo in the Piedmont, the Spanish wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zelkova Serrata
''Zelkova serrata'' (Japanese zelkova, Japanese elm or keyaki or keaki; ja, 欅 (ケヤキ) keyaki /槻 (ツキ) tsuki; ; ko, 느티나무 neutinamu) is a species of the genus ''Zelkova'' native plant, native to Japan, Korea, eastern China and Taiwan.Flora of China''Zelkova serrata''/ref>Andrews, S. (1994). Tree of the year: Zelkova. ''Int. Dendrol. Soc. Yearbook'' 1993: 11-30. It is often grown as an ornamental tree, and used in bonsai. There are two variety (biology), varieties, ''Zelkova serrata'' var. ''serrata'' in Japan and mainland eastern Asia, and ''Zelkova serrata'' var. ''tarokoensis'' (Hayata) Li on Taiwan which differs from the type in its smaller leaves with less deeply cut serration on the margins. Description ''Zelkova serrata'' is a medium-sized deciduous tree usually growing to tall. It is characterized by a short trunk dividing into many upright and erect spreading stems forming a broad, round-topped head. The tree grows rapidly when young though the growth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulmus Rubra
''Ulmus rubra'', the slippery elm, is a species of elm native to eastern North America. Other common names include red elm, gray elm, soft elm, moose elm, and Indian elm. Description ''Ulmus rubra'' is a medium-sized deciduous tree with a spreading head of branches,Hillier & Sons. (1990). ''Hillier's Manual of Trees & Shrubs, 5th ed.''. David & Charles, Newton Abbot, UK commonly growing to , very occasionally over in height. Its heartwood is reddish-brown. The broad oblong to obovate leaves are long, rough above but velvety below, with coarse double-serrate margins, acuminate apices and oblique bases; the petioles are long.Bean, W. J. (1970). ''Trees & Shrubs Hardy in the British Isles'', 8th ed., p. 656. (2nd impression 1976) John Murray, London. The leaves are often tinged red on emergence, turning dark green by summer and a dull yellow in autumn. The perfect, apetalous, wind-pollinated flowers are produced before the leaves in early spring, usually in tight, short-s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulmus Thomasii
''Ulmus thomasii'', the rock elm or cork elm (or orme liège in Québec), is a deciduous tree native primarily to the Midwestern United States. The tree ranges from southern Ontario and Quebec, south to Tennessee, west to northeastern Kansas, and north to Minnesota. Etymology The tree was named in 1902 for David Thomas, an American civil engineer who had first named and described the tree in 1831 as ''Ulmus racemosa''. Description ''Ulmus thomasii'' grows as a tree from tall, and may live for up to 300 years. Where forest-grown, the crown is cylindrical and upright with short branches, and is narrower than most other elms. Rock elm is also unusual among North American elms in that it is often monopodial.Bean, W. J. (1981). ''Trees and shrubs hardy in Great Britain'', 7th edition. Murray, London. The bark is grey-brown and deeply furrowed into scaly, flattened ridges. Many older branches have 3–4 irregular thick corky wings. It is for this reason the rock elm is somet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulmus Serotina
''Ulmus serotina'' Sarg., the September elm, is an autumn-flowering North American species of tree. It is uncommon beyond Tennessee; it is only very locally distributed through Illinois, Kentucky, Arkansas, Mississippi, Oklahoma, Alabama, and Georgia, and disjunct populations into Nuevo León, Mexico. It grows predominantly on limestone bluffs and along streams to elevations of 400 m.Duncan, W. H., & Duncan, M. B. (2000). ''Trees of the Southeastern United States'', 234–238. Athens, Georgia, USA. Description Rarely exceeding 20 m in height, the tree has a rounded crown with spreading to pendulous branches. The glabrous young shoots become progressively corky-winged with age, and bear oblong to obovate leaves <8 cm long. The wind-pollinated |
Ulmus Pumila
''Ulmus pumila'', the Siberian elm, is a tree native to Asia. It is also known as the Asiatic elm and dwarf elm, but sometimes miscalled the 'Chinese Elm' (''Ulmus parvifolia''). ''U. pumila'' has been widely cultivated throughout Asia, North America, Argentina, and southern Europe, becoming naturalized in many places, notably across much of the United States. Description The Siberian elm is usually a small to medium-sized, often bushy, deciduous tree growing to tall, the diameter at breast height to . The bark is dark gray, irregularly longitudinally fissured. The branchlets are yellowish gray, glabrous or pubescent, unwinged and without a corky layer, with scattered lenticels. The winter buds dark brown to red-brown, globose to ovoid. The petiole is , pubescent, the leaf blade elliptic-ovate to elliptic-lanceolate, , the colour changing from dark green to yellow in autumn.Fu, L., Xin, Y. & Whittemore, A. (2002). Ulmaceae, in Wu, Z. & Raven, P. (eds) ''Flora of China ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulmus Procera
The field elm (''Ulmus minor'') cultivar 'Atinia' , commonly known as the English elm, formerly common elm and horse may, Republished 1978 by EP Publishing, Wakefield. and more lately the Atinian elm was, before the spread of Dutch elm disease, the most common field elm in central southern England, though not native there, and one of the largest and fastest-growing deciduous trees in Europe. R. H. Richens noted that elm populations exist in north-west Spain and northern Portugal, and on the Mediterranean coast of France that "closely resemble the English elm" and appear to be "trees of long standing" in those regions rather than recent introductions. Augustine Henry had earlier noted that the supposed English elms planted extensively in the Royal Park at Aranjuez from the late 16th century onwards, specimens said to have been introduced from England by Philip IIRichens, R. H., ''Elm'' (Cambridge, 1983), p.276 and "differing in no respects from the English elm in England", b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
