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Olaf Hagerup
Olaf Hagerup (29 September 1889 – 2 March 1961) was a Danish botanist. He studied botany at the University of Copenhagen from 1911 under the professors Eugenius Warming, Christen C. Raunkiær, L. Kolderup Rosenvinge og W. Johannsen. He took his Ph.D. from the same university in 1930. From 1934 to 1960, he was superintendent at the Botanical Museum of the University of Copenhagen. Hagerup’s scientific works concern evolution, polyploidy and pollination, among other things. He showed that the tetraploid Empetrum hermaphroditum is a separate species from the diploid Empetrum nigrum. He thereby initiated the use of chromosome numbers in systematic botany, a field later known as cytotaxonomy. He put forward the hypothesis that the ploidy level is an important factor in the distribution and ecology of plant species. In contrast, another of his scientific ideas has been disproven by later modern research – the idea of a direct ancestry of the ''centrosperms'' (approximately ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denmark
) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of Denmark , established_title = Consolidation , established_date = 8th century , established_title2 = Christianization , established_date2 = 965 , established_title3 = , established_date3 = 5 June 1849 , established_title4 = Faroese home rule , established_date4 = 24 March 1948 , established_title5 = EEC accession , established_date5 = 1 January 1973 , established_title6 = Greenlandic home rule , established_date6 = 1 May 1979 , official_languages = Danish , languages_type = Regional languages , languages_sub = yes , languages = GermanGerman is recognised as a protected minority language in the South Jutland area of Denmark. , demonym = , capital = Copenhagen , largest_city = capital , coordinates = , ethnic_groups = , ethnic_gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytotaxonomy
Cytotaxonomy is the classification of organisms using comparative studies of chromosomes during mitosis. Description Cytotaxonomy is a branch of taxonomy that uses the characteristics of cellular structures to classify organisms. In cytotaxonomy, the chromosomal configuration of an organism is the most widely used parameter to infer the relationship between two organisms. The inference of species relationships is based on the assumption that closely related species share similar characteristics in their chromosomal setup (referred to as karyotype). By analysing the similarities and differences in the chromosomes, karyotype evolution and species evolution can be reconstructed. The number, structure, and behaviour of chromosomes is of great value in taxonomy, with chromosome number being the most widely used and quoted character. Chromosome numbers are usually determined at the metaphase stage during mitosis. Usually, the diploid chromosome number (2n) is referenced, unless dealing w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hannu Ahokas
Hannu, Hennu or Henenu was an Egyptian noble, serving as ''m-r-pr'' "majordomo" to Mentuhotep III in the 20th century BC. He reportedly re-opened the trade routes to Punt and Libya for the Middle Kingdom of Egypt. He was buried in a tomb in Deir el-Bahri, in the Theban Necropolis, which has been catalogued as TT313. He is known from two inscriptions, in Wadi Hammamat no. 114 (ca. 2000 BC) as ''hnw'' and in his Deir el-Bahari tomb as ''hnnw''. It is unclear whether the two inscriptions refer to the same person. William C. Hayes postulated their identity while Herbert Eustis Winlock was hesitant to identify them. James P. Allen considers ''hnw'' a successor of ''hnnw'' as the pharaoh's ''m-r-pr''. Travels In the eighth year of the reign of Mentuhotep III, Hannu set out from Coptos at the head of a three-thousand-man strong army, crossed the mountainous Eastern Desert by way of Wadi Hammamat, and went on to the coast of the Red Sea. Inscriptions Hannu wrote of his expedition in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vaccinium
''Vaccinium'' is a common and widespread genus of shrubs or dwarf shrubs in the heath family (Ericaceae). The fruits of many species are eaten by humans and some are of commercial importance, including the cranberry, blueberry, bilberry (whortleberry), lingonberry (cowberry), and huckleberry. Like many other ericaceous plants, they are generally restricted to acidic soils. Description The plant structure varies between species: some trail along the ground, some are dwarf shrubs, and some are larger shrubs perhaps tall. Some tropical species are epiphytic. Stems are usually woody. Flowers are epigynous with fused petals, and have long styles that protrude from their bell-shaped corollas. Stamens have anthers with extended tube-like structures called "awns" through which pollen falls when mature. Inflorescences can be axillary or terminal. The fruit develops from an inferior ovary, and is a four- or five-parted berry; it is usually brightly coloured, often being red or bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doris Löve
Doris Benta Maria Löve, ''née'' Wahlén (born 2 January 1918 in Kristianstad – deceased 25 February 2000 in San Jose, California) was a Swedish systematic botanist, particularly active in the Arctic. Biography Doris Löve was born in Kristianstad, Sweden. She studied botany at Lund University from 1937. She married her fellow student and colleague, the Icelander Áskell Löve. She received her PhD in botany in 1944. She focused her doctorate on the sexuality of ''Melandrium''. After their studies, the couple moved to Iceland. They moved to Winnipeg in 1951, to Montreal in 1955, and to Boulder in 1965. At universities where Áskell Löve taught, Doris Löve could not hold a faculty position at the same time as her husband. They finally moved to San Jose, California, in 1974. Together, Áskell and Doris Löve undertook numerous investigations of the chromosome numbers of plants and their use in plant systematics. They published numerous accounts in this field, and are con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Áskell Löve
Áskell Löve (20 October 1916 – 29 May 1994) was an Icelandic systematic botanist, particularly active in the Arctic. Education Áskell studied botany at Lund University, Sweden, from 1937. He received his PhD in 1942 in botany and a D.Sc. degree in genetics the year after. From 1941 to 1945, he was a research associate at Lund University and a corresponding geneticist at the University of Iceland. Work In 1945, where he served as director of ''Institute of Botany and Plant Breeding'' at the University of Iceland 1945–1951. Then, the family moved to North America, where Áskell became associate professor of botany at the University of Manitoba, Canada. In 1956, he became ''Professeur de Recherches'' at Université de Montréal and, in 1964 professor of biology at the University of Colorado at Boulder, which he remained until 1974. Áskell was awarded a Guggenheim fellow in 1963 and elected member of the Icelandic Academy of Sciences. He was a co-founder of the Flor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cranberry
Cranberries are a group of evergreen dwarf shrubs or trailing vines in the subgenus ''Oxycoccus'' of the genus '' Vaccinium''. In Britain, cranberry may refer to the native species '' Vaccinium oxycoccos'', while in North America, cranberry may refer to ''Vaccinium macrocarpon''. ''Vaccinium oxycoccos'' is cultivated in central and northern Europe, while ''Vaccinium macrocarpon'' is cultivated throughout the northern United States, Canada and Chile. In some methods of classification, ''Oxycoccus'' is regarded as a genus in its own right. They can be found in acidic bogs throughout the cooler regions of the Northern Hemisphere. Cranberries are low, creeping shrubs or vines up to long and in height; they have slender, wiry stems that are not thickly woody and have small evergreen leaves. The flowers are dark pink, with very distinct ''reflexed'' petals, leaving the style and stamens fully exposed and pointing forward. They are pollinated by bees. The fruit is a berry th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wettstein System
A system of plant taxonomy, the Wettstein system recognised the following main groups, according to Richard Wettstein's ''Handbuch der Systematischen Botanik'' (1901–1924). 3rd edition (1924) Outline Synopsis * Flagellatae p. 65 * Myxophyta p. 69 * Schizophyta ** Schizophyceae ** Schizomycetes * Zygophyta ** Peridinieae ** Bacillarieae *** Centricae *** Pennatae ** Conjugatae * Phaeophytae * Rhodophyta ** Bangieae ** Florideae * Euphallophyta ** Chlorophyceae ** Fungi *** Eumycetes **** Phycomycetes **** Ascomycetes **** Basidiomycetes *** Lichenes **** Ascolichenes **** Basidiolichenes * Cormophyta ** Archegoniatae *** Bryophyta **** Musci **** Hepaticae *** Pteridophyta **** Psilophytinae **** Lycopodiinae **** Psilotinae **** Equisetinae **** Isoëtinae **** Filicinae **** Cycadofilicinae ** Anthophyta *** Gymnospermae **** Cycadinae **** Bennettitinae **** Cordaitinae **** Gingkoinae **** Coniferae **** Gnetinae *** Angiospermae p. 467 **** Dicotyledone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Empetraceae
The Ericaceae are a family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with c.4250 known species spread across 124 genera, making it the 14th most species-rich family of flowering plants. The many well known and economically important members of the Ericaceae include the cranberry, blueberry, huckleberry, rhododendron (including azaleas), and various common heaths and heathers (''Erica'', '' Cassiope'', '' Daboecia'', and ''Calluna'' for example). Description The Ericaceae contain a morphologically diverse range of taxa, including herbs, dwarf shrubs, shrubs, and trees. Their leaves are usually evergreen, alternate or whorled, simple and without stipules. Their flowers are hermaphrodite and show considerable variability. The petals are often fused (sympetalous) with shapes ranging from narrowly tubular to funnelform or widely urn-shaped. The corollas are usually radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flowering Plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of broad-leaved trees, shrubs and vines, and most aquatic plants. The term "angiosperm" is derived from the Greek words ἀγγεῖον / ('container, vessel') and σπέρμα / ('seed'), meaning that the seeds are enclosed within a fruit. They are by far the most diverse group of land plants with 64 orders, 416 families, approximately 13,000 known genera and 300,000 known species. Angiosperms were formerly called Magnoliophyta (). Angiosperms are distinguished from the other seed-producing plants, the gymnosperms, by having flowers, xylem consisting of vessel elements instead of tracheids, endosperm within their seeds, and fruits that completely envelop the seeds. The ancestors of flowering plants diverged from the common ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gnetophyta
Gnetophyta () is a division of plants (alternatively considered the subclass Gnetidae or order Gnetales), grouped within the gymnosperms (which also includes conifers, cycads, and ginkgos), that consists of some 70 species across the three Relict (biology), relict genera: ''Gnetum'' (Family (biology), family Gnetaceae), ''Welwitschia'' (family Welwitschiaceae), and ''Ephedra (genus), Ephedra'' (family Ephedraceae). Fossilized pollen attributed to a close relative of ''Ephedra'' has been dated as far back as the Early Cretaceous. Though diverse in the Early Cretaceous, only three Family (biology), families, each containing a single genus, are still alive today. The primary difference between gnetophytes and other gymnosperms is the presence of vessel elements, a system of conduits that transport water within the plant, similar to those found in flowering plants. Because of this, gnetophytes were once thought to be the closest gymnosperm relatives to flowering plants, but more rece ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
