|
Water-plantain
''Alisma'' is a genus of flowering plants in the family Alismataceae, members of which are commonly known as water-plantains. The genus consists of aquatic plants with leaves either floating or submerged, found in a variety of still water habitats around the world (nearly worldwide). The flowers are hermaphrodite, and are arranged in panicles, racemes, or umbels. ''Alisma'' flowers have six stamens, numerous free carpels in a single whorl, each with 1 ovule, and subventral styles. The fruit is an achene with a short beak. The nineteenth century British art and social critic John Ruskin believed that the particular curve of the leaf-ribs of ''Alisma'' represented a model of 'divine proportion' and helped shape his theory of Gothic architecture.J. Mordaunt Crook, "Ruskinian Gothic" in The Ruskin Polygon: Essays on the Imagination of John Ruskin ed. John Dixon Hunt and Faith M. Holland (Manchester University Press, 1982) pp. 65–93. ''Copóg Phádraig'' ("Patrick's leaf") is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alismataceae
The water-plantains (Alismataceae) are a family of flowering plants, comprising 19 genera (17 extant and 2 fossil) and 117 species. The family has a cosmopolitan distribution, with the greatest number of species in temperate regions of the Northern Hemisphere. Most of the species are Herbaceous plant, herbaceous aquatic plants growing in marshes and ponds. Description Most Alismataceae are robust Perennial plant, perennials, but some may be Annual plant, annual or perennial, depending on water conditions — they are normally perennial in permanent waters, annual in more seasonal conditions but there are exceptions. The Plant stem, stems are corm-like or stoloniferous. Juvenile and submerse Leaf, leaves are often Leaf shape, linear, whilst more mature and emerse leaves can be linear to Leaf shape, ovate or even Leaf shape, sagittate. Most have a distinct Petiole (botany), petiole, with a sheathed base. The inflorescence is usually compound with whorls of branches, though som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alisma Plantago-aquatica
''Alisma plantago-aquatica'', also known as European water-plantain, common water-plantain or mad-dog weed, is a perennial flowering aquatic plant widespread across most of Europe and Asia, and apparently spread elsewhere in both the Old and New World. Description ''Alisma plantago-aquatica'' is a hairless plant that grows in shallow water, consists of a fibrous root, several basal long stemmed leaves long, and a triangular stem up to tall. It has branched inflorescence bearing numerous small flowers, across, with three round or slightly jagged, white or pale purple petals. The flowers open in the afternoon. There are three blunt green sepals and 6 stamens per flower. The carpels often exist as a flat single whorl. It flowers from June until August. The fruits appear as a ring of seeds inside each flower. Chemistry Chemical constituents of —rhizomes of ''Alisma orientale'' (syn. ''Alisma '' var. ''orientale'') as a traditional Chinese medicine—include alisol A 24-acet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alisma Gramineum
''Alisma gramineum'' is a small aquatic plant in the water-plantain family. It has several common names including narrowleaf water-plantain, ribbonleaf water-plantain or ribbon-leaved water-plantain, and grass-leaved water-plantain. It grows in mud or submerged in shallow fresh or brackish water in marshy areas. Description The leaves and tiny purple-tinted white flowers may be submersed or not. When the flowers grow underwater they are cleistogamous, meaning they stay closed and self-pollinate. When the flowers grow above water they open. The leaves above the surface are stiff and wide, but submerged leaves are ribbon-like. The fruit is a ring of dry nutlets. Reproduction is by seed or from division of the corm. Distribution and habitat ''Alisma gramineum'' is widespread across temperate and subarctic portions of Asia and Europe and North Africa from France and Libya to China and Yakutsk. It is reported from much of Canada from British Columbia to Quebec, as well as most of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alisma × Bjoerkqvistii
''Alisma'' is a genus of flowering plants in the family Alismataceae, members of which are commonly known as water-plantains. The genus consists of aquatic plants with leaves either floating or submerged, found in a variety of still water habitats around the world (nearly worldwide). The flowers are hermaphrodite, and are arranged in panicles, racemes, or umbels. ''Alisma'' flowers have six stamens, numerous free carpels in a single whorl, each with 1 ovule, and subventral styles. The fruit is an achene with a short beak. The nineteenth century British art and social critic John Ruskin believed that the particular curve of the leaf-ribs of ''Alisma'' represented a model of 'divine proportion' and helped shape his theory of Gothic architecture.J. Mordaunt Crook, "Ruskinian Gothic" in The Ruskin Polygon: Essays on the Imagination of John Ruskin ed. John Dixon Hunt and Faith M. Holland (Manchester University Press, 1982) pp. 65–93. ''Copóg Phádraig'' ("Patrick's leaf") is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golden Ratio
In mathematics, two quantities are in the golden ratio if their ratio is the same as the ratio of their sum to the larger of the two quantities. Expressed algebraically, for quantities a and b with a > b > 0, where the Greek letter phi ( or \phi) denotes the golden ratio. The constant \varphi satisfies the quadratic equation \varphi^2 = \varphi + 1 and is an irrational number with a value of The golden ratio was called the extreme and mean ratio by Euclid, and the divine proportion by Luca Pacioli, and also goes by several other names. Mathematicians have studied the golden ratio's properties since antiquity. It is the ratio of a regular pentagon's diagonal to its side and thus appears in the construction of the dodecahedron and icosahedron. A golden rectangle—that is, a rectangle with an aspect ratio of \varphi—may be cut into a square and a smaller rectangle with the same aspect ratio. The golden ratio has been used to analyze the proportions of natural object ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Africa
North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in the west, to Egypt's Suez Canal. Varying sources limit it to the countries of Algeria, Libya, Morocco, and Tunisia, a region that was known by the French during colonial times as "''Afrique du Nord''" and is known by Arabs as the Maghreb ("West", ''The western part of Arab World''). The United Nations definition includes Morocco, Algeria, Tunisia, Libya, Egypt, Sudan, and the Western Sahara, the territory disputed between Morocco and the Sahrawi Republic. The African Union definition includes the Western Sahara and Mauritania but not Sudan. When used in the term Middle East and North Africa (MENA), it often refers only to the countries of the Maghreb. North Africa includes the Spanish cities of Ceuta and Melilla, and plazas de s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia and it is located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. Comprising the westernmost peninsulas of Eurasia, it shares the continental landmass of Afro-Eurasia with both Africa and Asia. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south and Asia to the east. Europe is commonly considered to be Boundaries between the continents of Earth#Asia and Europe, separated from Asia by the drainage divide, watershed of the Ural Mountains, the Ural (river), Ural River, the Caspian Sea, the Greater Caucasus, the Black Sea and the waterways of the Turkish Straits. "Europe" (pp. 68–69); "Asia" (pp. 90–91): "A commonly accepted division between Asia and E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexandre Louis Simon Lejeune
Alexandre Louis Simon Lejeune (23 December 1779 in Verviers – 28 December 1858 in Verviers) was a physician and botanist. In 1801 he entered the school of medicine in Paris, but was subsequently forced to abandon his studies due to military conscription. After finishing his military duties in late 1804, he relocated to Ensival as a physician. Three years later, he settled permanently in his hometown of Verviers. With Richard Courtois (1806–1835), he was co-author of "Compendium florae belgicae". He was a mentor to Marie-Anne Libert, who he introduced to Augustin Pyramis de Candolle. Libert named the genus ''Lejeunea'' (family Lejeuneaceae) in Lejeune's honor in 1820. Botanical works * ''Flore des environs de Spa'', 1811 - Flora native to the environs of Spa. * ''Revue de la flore des environs de Spa'', 1824 - Review of flora native to the environs of Spa. * ''De Libertia, novo graminum genere, Commentatio'' 1825 - On the genus ''Libertia ''Libertia'' is a genus of mon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area of , about 30% of Earth's total land area and 8.7% of Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilizations. Its 4.7 billion people constitute roughly 60% of the world's population. In general terms, Asia is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, and on the north by the Arctic Ocean. The border of Asia with Europe is a historical and cultural construct, as there is no clear physical and geographical separation between them. It is somewhat arbitrary and has moved since its first conception in classical antiquity. The division of Eurasia into two continents reflects East–West cultural, linguistic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alisma Canaliculatum
''Alisma canaliculatum'', commonly known as channelled water plantain, is a species of plants in the Alismataceae. It is native to Japan, Korea, the Ryukyu Islands, Taiwan, the Kuril Islands, and China (Anhui, Fujian, Guizhou, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shandong, Sichuan, Zhejiang Zhejiang ( or , ; , also romanized as Chekiang) is an eastern, coastal province of the People's Republic of China. Its capital and largest city is Hangzhou, and other notable cities include Ningbo and Wenzhou. Zhejiang is bordered by Jiang ...). ''Alisma canaliculatum'' is a perennial herb with tubers up to 3 cm across. Leaves are lanceolate, up to 50 cm long. Flowers are white, borne in a branching panicle. References External linksPlants For a Future [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russia
Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the world, with its internationally recognised territory covering , and encompassing one-eighth of Earth's inhabitable landmass. Russia extends across Time in Russia, eleven time zones and shares Borders of Russia, land boundaries with fourteen countries, more than List of countries and territories by land borders, any other country but China. It is the List of countries and dependencies by population, world's ninth-most populous country and List of European countries by population, Europe's most populous country, with a population of 146 million people. The country's capital and List of cities and towns in Russia by population, largest city is Moscow, the List of European cities by population within city limits, largest city entirely within E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swamp
A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in creating this environment. Swamps vary in size and are located all around the world. The water of a swamp may be fresh water, brackish water, or seawater. Freshwater swamps form along large rivers or lakes where they are critically dependent upon rainwater and seasonal flooding to maintain natural water level fluctuations.Hughes, F.M.R. (ed.). 2003. The Flooded Forest: Guidance for policy makers and river managers in Europe on the restoration of floodplain forests. FLOBAR2, Department of Geography, University of Cambridge, Cambridge, UK. 96 p. Saltwater swamps are found along tropical and subtropical coastlines. Some swamps have hammock (ecology), hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> North Africa")
.svg "Click for more on -> Europe")
