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Spear Thistle
''Cirsium vulgare'', commonly known as spear thistle, bull thistle, or common thistle, is a species of the Asteraceae genus ''Cirsium'', native throughout most of Europe (north to 66°N, locally 68°N), Western Asia (east to the Yenisei Valley), and northwestern Africa (Atlas Mountains).''Flora Europaea''''Cirsium vulgare''/ref> It is also naturalised in North America, Africa, and Australia and is an invasive weed in several regions. It is the national flower of Scotland. The plant provides a great deal of nectar for pollinators. It was rated in the top 10 for most nectar production (nectar per unit cover per year) in a UK plants survey conducted by the AgriLand project which is supported by the UK Insect Pollinators Initiative. Marsh thistle, ''Cirsium palustre'', was ranked in first place while this thistle was ranked in sixth place. It also was a top producer of nectar sugar in another study in Britain, ranked third with a production per floral unit of (2300 ± 400 μg). ...
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Cirsium Horridulum
''Cirsium horridulum'', called bristly thistle, purple thistle, or yellow thistle is a North American species of plants in the tribe Cardueae within the family Asteraceae. It is an annual or biennial. The species is native to the eastern and southern United States from New England to Florida, Texas, and Oklahoma as well as to Mexico, Belize, Guatemala, Honduras, and the Bahamas. Thomas Nuttall (1786-1859) described var. ''megacanthum'' as "one of the most terribly armed plants in the genus." ''Cirsium horridulum'' is a biennial herb up to tall, with a large taproot and fleshy side roots that sometimes sprout new shoots. Leaves are up to long with thick, sharp spines along the edges. There are usually several flower heads, also with sharp spines, each head with disc florets but no ray florets. Flower color varies from one plant to the next: white, yellow, pink, red or purple. ; ; ; Varieties * ''Cirsium horridulum'' var. ''horridulum'' - from Maine to Guatemala * ''Cirsium ...
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Biennial Plant
A biennial plant is a flowering plant that, generally in a temperate climate, takes two years to complete its biological life cycle. Background In its first year, the biennial plant undergoes primary growth, during which its vegetative structures (leaves, stems, and roots) develop. Usually, the stem of the plant remains short and the leaves are low to the ground, forming a rosette. After one year's growing season, the plant enters a period of dormancy for the colder months. Many biennials require a cold treatment, or vernalization before they will flower. During the next spring or summer, the stem of the biennial plant elongates greatly, or "bolts". The plant then flowers, producing fruits and seeds before it finally dies. There are far fewer biennials than either perennial plants or annual plants. Biennials do not always follow a strict two-year life cycle: most plants in the wild can take three or more years to mature. Rosette leaf size has been found to predict when a pla ...
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Disturbed Ground
In ecology, a disturbance is a change in environmental conditions that causes a pronounced change in an ecosystem. Disturbances often act quickly and with great effect, to alter the physical structure or arrangement of biotic and abiotic elements. A disturbance can also occur over a long period of time and can impact the biodiversity within an ecosystem. Ecological disturbances include fires, flooding, storms, insect outbreaks, trampling, human presence, earthquakes, plant diseases, infestations, volcanic eruptions, impact events, etc. Not only invasive species can have a profound effect on an ecosystem, native species can also cause disturbance by their behavior. Disturbance forces can have profound immediate effects on ecosystems and can, accordingly, greatly alter the natural community’s population size or species richness. Because of these and the impacts on populations, disturbance determines the future shifts in dominance, various species successively becoming domin ...
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Ruderal Species
A ruderal species is a plant species that is first to colonize disturbed lands. The disturbance may be natural for example, wildfires or avalanchesor the consequences of human activities, such as construction ( of roads, of buildings, mining, etc.) or agriculture (abandoned fields, irrigation, etc.). The term '' ruderal'' originates from the Latin word '' rudus'', meaning " rubble". Ruderal species typically dominate the disturbed area for a few years, gradually losing the competition to other native species. However, in extreme disturbance circumstances, such as when the natural topsoil is covered with a foreign substance, a single-species ruderal community may become permanently established. In addition, some ruderal invasive species may have such a competitive advantage over the native species that they, too, may permanently prevent a disturbed area from returning to its original state despite natural topsoil. Features Features contributing to a species' success as ruder ...
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Carduus
''Carduus'' is a genus of flowering plants in the family Asteraceae, and the tribe Cardueae, one of two genera considered to be true thistles, the other being ''Cirsium''. Plants of the genus are known commonly as plumeless thistles.''Carduus''.
Integrated Taxonomic Information System (ITIS).
''Carduus''.
Flora of North America.
They are native to temperate Eurasia and North Africa, and several are known elsewhere as . This genus is noted for its disproportionat ...
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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 dispersal mechanism for the achenes that contain the seeds. 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. In genera such as '' Bidens'' the pappus has hooks that function in mechanical dispersal. 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 vital role in the wind-aided dispersal of its seeds. By creating a separated vortex ri ...
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Seed
In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds are the product of the ripened ovule, after the embryo sac is fertilization, fertilized by Pollen, sperm from pollen, forming a zygote. The embryo within a seed develops from the zygote and grows within the mother plant to a certain size before growth is halted. The formation of the seed is the defining part of the process of reproduction in seed plants (spermatophytes). Other plants such as ferns, mosses and marchantiophyta, liverworts, do not have seeds and use water-dependent means to propagate themselves. Seed plants now dominate biological Ecological niche, niches on land, from forests to grasslands both in hot and cold climates. In the flowering plants, the ovary ripens into a fruit which contains the seed and serves to disseminate ...
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Floret
This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary of leaf morphology. For other related terms, see Glossary of phytopathology, Glossary of lichen terms, and List of Latin and Greek words commonly used in systematic names. A B ...
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Inflorescence
In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a main axis (Peduncle (botany), peduncle) and by the timing of its flowering (determinate and indeterminate). Morphology (biology), Morphologically, an inflorescence is the modified part of the Shoot (botany), shoot of spermatophyte, seed plants where flowers are formed on the axis of a plant. The modifications can involve the length and the nature of the internode (botany), internodes and the phyllotaxis, as well as variations in the proportions, compressions, swellings, adnations, connations and reduction of main and secondary axes. One can also define an inflorescence as the reproductive portion of a plant that bears a cluster of flowers in a specific pattern. General characteristics Inflorescences are described by many different charact ...
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Flower
Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, modified leaves; corolla, the petals; androecium, the male reproductive unit consisting of stamens and pollen; and gynoecium, the female part, containing style and stigma, which receives the pollen at the tip of the style, and ovary, which contains the ovules. When flowers are arranged in groups, they are known collectively as inflorescences. Floral growth originates at stem tips and is controlled by MADS-box genes. In most plant species flowers are heterosporous, and so can produce sex cells of both sexes. Pollination mediates the transport of pollen to the ovules in the ovaries, to facilitate sexual reproduction. It can occur between different plants, as in cross-pollination, or between flowers on the same plant or even the same f ...
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Taproot
A taproot is a large, central, and dominant root from which other roots sprout laterally. Typically a taproot is somewhat straight and very thick, is tapering in shape, and grows directly downward. In some plants, such as the carrot, the taproot is a storage organ so well developed that it has been cultivated as a vegetable. The taproot system contrasts with the adventitious- or fibrous-root system of plants with many branched roots, but many plants that grow a taproot during germination go on to develop branching root structures, although some that rely on the main root for storage may retain the dominant taproot for centuries—for example, ''Welwitschia''. Description Dicots, one of the two divisions of flowering plants (angiosperms), start with a taproot, which is one main root forming from the enlarging radicle of the seed. The tap root can be persistent throughout the life of the plant but is most often replaced later in the plant's development by a fibrous root system. ...
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Leaf
A leaf (: leaves) is a principal appendage of the plant stem, stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, flower, and fruit collectively form the Shoot (botany), shoot system. In most leaves, the primary Photosynthesis, photosynthetic Tissue (biology), tissue is the palisade mesophyll and is located on the upper side of the blade or lamina of the leaf, but in some species, including the mature foliage of ''Eucalyptus'', palisade mesophyll is present on both sides and the leaves are said to be isobilateral. The leaf is an integral part of the stem system, and most leaves are flattened and have distinct upper (Glossary of botanical terms#adaxial, adaxial) and lower (Glossary of botanical terms#abaxial, abaxial) surfaces that differ in color, Trichome, hairiness, the number of stomata (pores that intake and output gases), the amount and ...
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