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Crataegus Collina
''Crataegus collina'' is a type of hawthorn that is closely related to ''C. punctata'', the dotted hawthorn, and sometimes considered to be the same species. A sample of ''C. collina'' and ''C. punctata'' has suggested that ''C. collina'' is polyploid, and ''C. punctata'' is diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ..., but a wider sample is needed to confirm that this is generally the case. References collina Flora of the United States Taxa named by Alvan Wentworth Chapman {{Crataegus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alvan Wentworth Chapman
Alvan Wentworth Chapman (September 28, 1809 – April 6, 1899) was an American physician and pioneering botanist in the study of flora of the American Southeast.Makers of American Botany, Harry Baker Humphrey, Ronald Press Company, Library of Congress Card Number 61-18435 He wrote ''Flora of the Southern United States'', the first comprehensive description of US plants in any region beyond the northeastern states. Education He was born in Southampton, Massachusetts, the youngest of five children. In 1830, he graduated from Amherst College with a degree in classics. He moved to Georgia and then Florida where he held various teaching positions, and married Mary Ann Hancock in 1839. In the early 1840s, he received a medical education, acquiring his MD in 1846. In 1847, he settled in Apalachicola, Florida, remaining there for the rest of his life working as a physician and botanist, collaborating with Asa Gray. Botanical works His botanical interest seems to have started when he liv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crataegus Punctata
''Crataegus punctata'' is a species of hawthorn known by the common names dotted hawthorn or white haw that is native to most of the eastern United States and eastern Canada. While some sources claim it is the state flower of Missouri, the actual legislation does not identify an exact species. Furthermore, the Missouri Department of Conservation asserts the ''Crataegus mollis'' was specifically designated as the state flower. Description Although many North American hawthorns are polyploid and reproduce by apomixis, this species is apparently diploid and sexual, at least throughout Ontario, Canada. The name white haw refers to its distinctive pale (grey) bark, which is particularly noticeable in the winter landscape. The plant is a bush or small tree to about 7 meters in height and very thorny, particularly on the trunk. The flower has three to five styles and approximately 20 stamens, and the fruit is a pome-type polypyrenous drupe which contains three to five pits. Anther col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyploid
Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei ( eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contains one or more chromosomes and comes from each of two parents, resulting in pairs of homologous chromosomes between sets. However, some organisms are polyploid. Polyploidy is especially common in plants. Most eukaryotes have diploid somatic cells, but produce haploid gametes (eggs and sperm) by meiosis. A monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Males of bees and other Hymenoptera, for example, are monoploid. Unlike animals, plants and multicellular algae have life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis, the sporophyte generation is diploid and produces spores by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diploid
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair, which chromosomes naturally exist as. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present (the "ploidy level"): monoploid (1 set), diploid (2 sets), triploid (3 sets), tetraploid (4 sets), pentaploid (5 sets), hexaploid (6 sets), heptaploid or septaploid (7 sets), etc. The generic term polyploid is often used to describe cells with three or more chromosome sets. Virtually all sexually reproducing organisms are made up of somatic cells that are diploid or greater, but ploidy level may vary widely between different organisms, between different tissues within the same organism, and at different stages in an organism's life cycle. Half ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of The United States
The native flora of the United States includes about 17,000 species of vascular plants, plus tens of thousands of additional species of other plants and plant-like organisms such as algae, lichens and other fungi, and mosses. About 3,800 additional non-native species of vascular plants are recorded as established outside of cultivation in the U.S., as well as a much smaller number of non-native non-vascular plants and plant relatives. The United States possesses one of the most diverse temperate floras in the world, comparable only to that of China. Several biogeographic factors contribute to the richness and diversity of the U.S. flora. While most of the United States has a temperate climate, Alaska has vast arctic areas, the southern part of Florida is tropical, as well as Hawaii (including high mountains), and the U.S. territories in the Caribbean and the Pacific, and alpine summits are present on many western mountains, as well as a few in the Northeast. The U.S. coastline ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
