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Pleiacanthus Spinosus
''Pleiacanthus'' is a monotypic genusLee, J., et al. (2002)Phylogeny of ''Stephanomeria'' and related genera (Compositae–Lactuceae) based on analysis of 18S–26S nuclear rDNA ITS and ETS sequences.''Am J Bot'' 89 160-8. of flowering plants in the family Asteraceae containing the single species ''Pleiacanthus spinosus'' (formerly ''Stephanomeria spinosa''), which is known by the common name thorn skeletonweed, or thorny skeletonweed. It is native to the western United States from Montana and Idaho to southern California and Arizona, where it grows in many types of mostly dry habitat from deserts to mountains. It is a spindly subshrub producing several slender stems up to 40 or 50 centimeters tall from a woody caudex. The stems divide many times into short, rigid branches which narrow to sharp thorn-tips. The plant is mostly hairless except for brownish woolly tufts at the base and below the basal leaves. The leaves are small and linear on the lower stem, and reduced to scale-like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Nuttall
Thomas Nuttall (5 January 1786 – 10 September 1859) was an England, English botany, botanist and zoologist who lived and worked in America from 1808 until 1841. Nuttall was born in the village of Long Preston, near Settle, North Yorkshire, Settle in the West Riding of Yorkshire and spent some years as an apprentice printer in England. Soon after going to the United States he met professor Benjamin Smith Barton in Philadelphia. Barton encouraged his strong interest in natural history. Early explorations in the United States In 1810 he travelled to the Great Lakes and in 1811 travelled on the Astor Expedition led by William Price Hunt on behalf of John Jacob Astor up the Missouri River. Nuttall was accompanied by the English botanist John Bradbury (naturalist), John Bradbury, who was collecting plants on behalf of Liverpool botanical gardens. Nuttall and Bradbury left the party at the trading post with the Arikara Indians in South Dakota, and continued farther upriver with Rams ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture. Typically, they also look different from the parts of the flower, such as the petals or sepals. A plant having bracts is referred to as bracteate or bracteolate, while one that lacks them is referred to as ebracteate and ebracteolate, without bracts. Variants Some bracts are brightly-coloured and serve the function of attracting pollinators, either together with the perianth or instead of it. Examples of this type of bract include those of ''Euphorbia pulcherrima'' (poinsettia) and ''Bougainvillea'': both of these have large colourful bracts surrounding much smaller, less colourful flowers. In grasses, each floret (flower) is enclosed in a pair of papery bracts, called the lemma (lower bract) and p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of California
Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous) native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms '' gut flora'' or '' skin flora''. Etymology The word "flora" comes from the Latin name of Flora, the goddess of plants, flowers, and fertility in Roman mythology. The technical term "flora" is then derived from a metonymy of this goddess at the end of the sixteenth century. It was first used in poetry to denote the natural vegetation of an area, but soon also assumed the meaning of a work cataloguing such vegetation. Moreover, "Flora" was used to refer to the flowers of an artificial garden in the seventeenth century. The distinction between vegetation (the general appearance of a community) and flora (the taxonomic composition of a community) was first made by Jules Thurmann (1849). Prior to this, the two terms were used indiscriminately.Thurmann, J. (1849). ''Essai de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of Arizona
Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous) native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms '' gut flora'' or '' skin flora''. Etymology The word "flora" comes from the Latin name of Flora, the goddess of plants, flowers, and fertility in Roman mythology. The technical term "flora" is then derived from a metonymy of this goddess at the end of the sixteenth century. It was first used in poetry to denote the natural vegetation of an area, but soon also assumed the meaning of a work cataloguing such vegetation. Moreover, "Flora" was used to refer to the flowers of an artificial garden in the seventeenth century. The distinction between vegetation (the general appearance of a community) and flora (the taxonomic composition of a community) was first made by Jules Thurmann (1849). Prior to this, the two terms were used indiscriminately.Thurmann, J. (1849). ''Essai de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic Asteraceae Genera
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. In contrast, an oligotypic taxon contains more than one but only a very few subordinate taxa. Examples Just as the term ''monotypic'' is used to describe a taxon including only one subdivision, the contained taxon can also be referred to as monotypic within the higher-level taxon, e.g. a genus monotypic within a family. Some examples of monotypic groups are: Plants * In the order Amborellales, there is only one family, Amborellaceae and there is only one genus, '' Amborella'', and in this genus there is only one species, namely ''Amborella trichopoda.' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cichorieae
The Cichorieae (also called Lactuceae) are a tribe in the plant family Asteraceae that includes 93 genera, more than 1,600 sexually reproductive species and more than 7,000 Apomixis, apomictic species. They are found primarily in temperate regions of the Eastern Hemisphere. Cichorieae all have milky latex and flowerheads that only contain one type of Glossary of botanical terms#floret, floret. The genera ''Gundelia'' and ''Warionia'' only have Asteraceae#Floral heads, disk florets, while all other genera only have Asteraceae#Floral heads, ligulate florets. The genera that contain most species are ''Taraxacum'' (Crepidinae subtribe) with about 1,600 apomictic species, ''Hieracium'' with about 770 sexually reproducing and 5,200 apomictic species, and ''Pilosella'' with 110 sexually reproducing and 700 apomictic species (both Hieraciinae). Well-known members include lettuce, chicory, Taraxacum, dandelion, and Tragopogon, salsify. Description Most species are Herbaceous plant, herba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stephanomeria
''Stephanomeria'' is a genus of North American plants also known as wirelettuce, belonging to the tribe Cichorieae within the family Asteraceae.Lee, J., Baldwin, B., and Gottlieb, L.D.; ''Phylogeny of ''Stephanomeria'' and related genera (compositae-lactuceae) bed on analysis of 18S-26S nuclear rDNA ITS and ETS sequences''; American Journal of Botany. 2002; 89:160-168 ''Stephanomeria'' species are used as food plants by the larvae of some Lepidoptera species including '' Schinia scarletina'', which feeds exclusively on the genus. ; Annual species * ''Stephanomeria diegensis'' Gottlieb - San Diego wirelettuce - Baja California, southern California; Hybrid origin: ''S. exigua х S. virgata'' * '' Stephanomeria elata'' Nutt. - Santa Barbara wirelettuce - California and Oregon; 2n=32 * ''Stephanomeria exigua'' Nutt. - small wirelettuce - widespread throughout western United States + Baja California; 2n=16 * '' Stephanomeria hitchcockii'' Gand. - Kansas * ''Stephanomeria malheurensis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pappus (flower Structure)
In Asteraceae, the pappus is the modified calyx, the part of an individual floret, that surrounds the base of the corolla tube in flower. It functions as a wind-dispersal mechanism for the seeds. The term is sometimes used for similar structures in other plant families e.g. in certain genera of the Apocynaceae, although the pappus in Apocynaceae is not derived from the calyx of the flower. In Asteraceae, the pappus may be composed of bristles (sometimes feathery), awns, scales, or may be absent, and in some species, is too small to see without magnification. In genera such as ''Taraxacum'' or ''Eupatorium'', feathery bristles of the pappus function as a "parachute" which enables the seed to be carried by the wind. The name derives from the Ancient Greek word ''pappos'', Latin ''pappus'', meaning "old man", so used for a plant (assumed to be an ''Erigeron'' species) having bristles and also for the woolly, hairy seed of certain plants. The pappus of the dandelion plays a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achene
An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not open at maturity). Achenes contain a single seed that nearly fills the pericarp, but does not adhere to it. In many species, what is called the "seed" is an achene, a fruit containing the seed. The seed-like appearance is owed to the hardening of the fruit wall (pericarp), which encloses the solitary seed so closely as to seem like a seed coat. Examples The fruits of buttercup, buckwheat, caraway, quinoa, amaranth, and cannabis are typical achenes. The achenes of the strawberry are sometimes mistaken for seeds. The strawberry is an accessory fruit with an aggregate of achenes on its outer surface, and what is eaten is accessory tissue. A rose produces an aggregate of achene fruits that are encompassed within an expanded hypanthium (aka f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Head (botany)
A pseudanthium (Greek for "false flower"; ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, composite flowers, or capitula, which are special types of inflorescences in which anything from a small cluster to hundreds or sometimes thousands of flowers are grouped together to form a single flower-like structure. Pseudanthia take various forms. The real flowers (the florets) are generally small and often greatly reduced, but the pseudanthium itself can sometimes be quite large (as in the heads of some varieties of sunflower). Pseudanthia are characteristic of the daisy and sunflower family (Asteraceae), whose flowers are differentiated into ray flowers and disk flowers, unique to this family. The disk flowers in the center of the pseudanthium are actinomorphic and the corolla is fused into a tube. Flowers on the periphery are zygomorp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Per Axel Rydberg
Per Axel Rydberg (July 6, 1860 – July 25, 1931) was a Swedish-born, American botanist who was the first curator of the New York Botanical Garden Herbarium. Biography Per Axel Rydberg was born in Odh, Västergötland, Sweden and emigrated to the United States in 1882. From 1884 to 1890, he taught mathematics at Luther Academy in Wahoo, Nebraska, while he studied at the University of Nebraska. He graduated from the University of Nebraska–Lincoln (B.S. in 1891) and (M.A. in 1895). He earned his graduate degree from Columbia University (Ph.D. in 1898). After he graduated, Rydberg received a commission from the United States Department of Agriculture to undertake a botanical exploration of western Nebraska. He received another one in 1892 to explore the Black Hills of South Dakota, and in 1893 he was in the Sand Hills, again in western Nebraska. During this time he continued to teach at the Luther Academy. In 1900 Rydberg conducted field work in southeast Colorado. In 1901 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudex
A caudex (plural: caudices) of a plant is a stem, but the term is also used to mean a rootstock and particularly a basal stem structure from which new growth arises.pages 456 and 695 In the strict sense of the term, meaning a stem, "caudex" is most often used with plants that have a different stem morphology from the typical angiosperm dicotyledon stem: examples of this include palms, ferns, and cycads. The related term caudiciform, literally meaning stem-like, is sometimes used to mean pachycaul, thick-stemmed. Etymology The term is from the Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ... ''caudex'', a noun meaning "tree trunk". See also * Stipe References External links Bihrmann's Caudiciforms''Extensive listing of caudiciforms, images for most species'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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