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Secondary Growth
In botany, secondary growth is the growth that results from cell division in the cambia or lateral meristems and that causes the stems and roots to thicken, while primary growth is growth that occurs as a result of cell division at the tips of stems and roots, causing them to elongate, and gives rise to primary tissue. Secondary growth occurs in most seed plants, but monocots usually lack secondary growth. If they do have secondary growth, it differs from the typical pattern of other seed plants. The formation of secondary vascular tissues from the cambium is a characteristic feature of dicotyledons and gymnosperms. In certain monocots, the vascular tissues are also increased after the primary growth is completed but the cambium of these plants is of a different nature. In the living pteridophytes this feature is extremely rare, only occurring in '' Isoetes''. Lateral meristems In many vascular plants, secondary growth is the result of the activity of the two lateral me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree Swallowing Lamp Post
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only plants that are usable as lumber, or only plants above a specified height. But wider definitions include taller palms, tree ferns, bananas, and bamboos. Trees are not a monophyletic taxonomic group but consist of a wide variety of plant species that have independently evolved a trunk and branches as a way to tower above other plants to compete for sunlight. The majority of tree species are angiosperms or hardwoods; of the rest, many are gymnosperms or softwoods. Trees tend to be long-lived, some trees reaching several thousand years old. Trees evolved around 400 million years ago, and it is estimated that there are around three trillion mature trees in the world currently. A tree typically has many secondary branches supported clear of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vascular Cambium
The vascular cambium is the main growth tissue in the stems and roots of many plants exhibiting secondary growth, specifically in dicots such as buttercups and oak trees, gymnosperms such as pine trees, as well as in certain other vascular plants. It produces secondary xylem inwards, towards the pith, and secondary phloem outwards, towards the bark. Generally, more secondary xylem is produced than secondary phloem. In herbaceous plants, it occurs in the vascular bundles which are often arranged like beads on a necklace forming an interrupted ring inside the stem. In woody plants, it forms a cylinder of unspecialized meristem cells, as a continuous ring from which the new tissues are grown. Unlike the xylem and phloem, it does not transport water, minerals or food through the plant. Other names for the vascular cambium are the main cambium, wood cambium, or bifacial cambium. Occurrence Vascular cambia are found in all seed plants except for five angiosperm lineages whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sweet Potato
The sweet potato or sweetpotato (''Ipomoea batatas'') is a dicotyledonous plant in the morning glory family, Convolvulaceae. Its sizeable, starchy, sweet-tasting tuberous roots are used as a root vegetable, which is a staple food in parts of the world. Cultivars of the sweet potato have been bred to bear tubers with flesh and skin of various colors. Moreover, the young shoots and leaves are occasionally eaten as greens. The sweet potato and the potato are in the order Solanales, making them distant relatives. Although darker sweet potatoes are often known as "yams" in parts of North America, they are even more distant from actual yams, which are monocots in the order Dioscoreales. The sweet potato is native to the tropical regions of South America in what is present-day Ecuador. Of the approximately 50 genera and more than 1,000 species of Convolvulaceae, ''I. batatas'' is the only crop plant of major importance—some others are used locally (e.g., ''I. aquatica'' "ka ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carrot
The carrot ('' Daucus carota'' subsp. ''sativus'') is a root vegetable, typically orange in colour, though heirloom variants including purple, black, red, white, and yellow cultivars exist, all of which are domesticated forms of the wild carrot, ''Daucus carota'', native to Europe and Southwestern Asia. The plant probably originated in Iran and was originally cultivated for its leaves and seeds. The carrot is a biennial plant in the umbellifer family, Apiaceae. World production of carrots (combined with turnips) for 2022 was 42 million tonnes, led by China producing 44% of the total. The characteristic orange colour is from beta-carotene, making carrots a rich source of vitamin A. A myth that carrots help people to see in the dark was spread as propaganda in the Second World War, to account for the ability of British pilots to fight in the dark; the real explanation was the introduction of radar. Etymology The word is first recorded in English around 1530 and w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuber
Tubers are a type of enlarged structure that plants use as storage organs for nutrients, derived from stems or roots. Tubers help plants perennate (survive winter or dry months), provide energy and nutrients, and are a means of asexual reproduction. Stem tubers manifest as thickened rhizomes (underground stems) or stolons (horizontal connections between organisms); examples include the potato and Yam (vegetable), yam. The term ''root tuber'' describes modified lateral roots, as in sweet potatoes, cassava, and dahlias. Terminology The term originates from the Latin , meaning 'lump, bump, or swelling'. Some writers limit the definition of ''tuber'' to structures derived from Plant stem, stems, while others also apply the term to structures derived from roots., p. 124 Stem tubers A stem tuber forms from thickened rhizomes or stolons. The top sides of the tuber produce shoots that grow into typical stems and leaves and the undersides produce roots. They tend to form at the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potato
The potato () is a starchy tuberous vegetable native to the Americas that is consumed as a staple food in many parts of the world. Potatoes are underground stem tubers of the plant ''Solanum tuberosum'', a perennial in the nightshade family Solanaceae. Wild potato species can be found from the southern United States to southern Chile. Genetic studies show that the cultivated potato has a single origin, in the area of present-day southern Peru and extreme northwestern Bolivia. Potatoes were domesticated there about 7,000–10,000 years ago from a species in the '' S. brevicaule'' complex. Many varieties of the potato are cultivated in the Andes region of South America, where the species is indigenous. The Spanish introduced potatoes to Europe in the second half of the 16th century from the Americas. They are a staple food in many parts of the world and an integral part of much of the world's food supply. Following millennia of selective breeding, there are now over 5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tomato
The tomato (, ), ''Solanum lycopersicum'', is a plant whose fruit is an edible Berry (botany), berry that is eaten as a vegetable. The tomato is a member of the nightshade family that includes tobacco, potato, and chili peppers. It originated from and was domesticated in western South America. It was introduced to the Old World by the Spanish in the Columbian exchange in the 16th century. Tomato plants are vines, largely Annual plant, annual and vulnerable to frost, though sometimes living longer in greenhouses. The flowers are able to self-fertilise. Modern varieties have been bred to ripen uniformly red, in a process that has impaired the fruit's sweetness and flavor. There are thousands of cultivars, varying in size, color, shape, and flavor. Tomatoes are attacked by many insect pests and nematodes, and are subject to diseases caused by viruses and by mildew and blight fungi. The tomato has a strong savoury umami flavor, and is an important ingredient in cuisines around ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cork (material)
Cork is an impermeable buoyant material. It is the phellem layer of bark tissue which is harvested for commercial use primarily from '' Quercus suber'' (the cork oak), which is native to southwest Europe and northwest Africa. Cork is composed of suberin, a hydrophobic substance. Because of its impermeable, buoyant, elastic, and fire retardant properties, it is used in a variety of products, the most common of which is wine stoppers. The montado landscape of Portugal produces approximately half of the cork harvested annually worldwide, with Corticeira Amorim being the leading company in the industry. Cork was examined microscopically by Robert Hooke, which led to his discovery and naming of the cell. Cork composition varies depending on geographic origin, climate and soil conditions, genetic origin, tree dimensions, age (virgin or reproduction), and growth conditions. However, in general, cork is made up of suberin (average of about 40%), lignin (22%), polysaccharid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cork Oak
''Quercus suber'', commonly called the cork oak, is a medium-sized, evergreen oak tree in the section Quercus sect. Cerris, ''Quercus'' sect. ''Cerris''. It is the primary source of cork (material), cork for wine bottle stoppers and other uses, such as cork flooring and as the cores of cricket balls. It is native to southwest Europe and northwest Africa. In the Mediterranean basin the tree is an ancient species with fossil remnants dating back to the Tertiary period. It can survive for as long as two centuries. Typically, once it reaches 25 years old, its thick bark can be harvested for cork every 9 to 12 years without causing harm to the tree. It endures drought and makes little demand on the soil quality and is regarded as a defence against desertification. Cork oak woodlands are home to a multitude of animal and plant species. Since cork for sealing bottles is increasingly being displaced by other materials, these forests are at risk as part of the cultural landscape and as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cork (tissue)
Cork cambium (: cambia or cambiums) is a tissue found in many vascular plants as a part of the epidermis. It is one of the many layers of bark, between the cork and primary phloem. The cork cambium is a lateral meristem and is responsible for secondary growth that replaces the epidermis in roots and stems. It is found in woody and many herbaceous dicots, gymnosperms and some monocots (monocots usually lack secondary growth). It is one of the plant's meristems – the series of tissues consisting of embryonic disk (incompletely differentiated) cells from which the plant grows. The function of cork cambium is to produce the cork, a tough protective material.Junikka, L. (1994) "Macroscopic bark terminology". ''IAWA Journal'' 15(1): 3–45Trockenbrodt, M. (1990) "Survey and discussion of the terminology used in bark anatomy". ''IAWA Bulletin, New Series'' 11: 141–166 Synonyms for cork cambium are bark cambium, peri-cambium and phellogen. Phellogen is defined as the meristematic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidermis (botany)
The epidermis (from the Greek language, Greek ''ἐπιδερμίς'', meaning "over-skin") is a single layer of cells that covers the leaf, leaves, flowers, roots and Plant stem, stems of plants. It forms a boundary between the plant and the external environment. The epidermis serves several functions: it protects against water loss, regulates gas exchange, secretes metabolic compounds, and (especially in roots) absorbs water and mineral nutrients. The epidermis of most leaves shows Anatomical terms of location#Dorsal and ventral, dorsoventral anatomy: the upper (adaxial) and lower (abaxial) surfaces have somewhat different construction and may serve different functions. Woody stems and some other stem structures such as potato tubers produce a secondary covering called the periderm that replaces the epidermis as the protective covering. Description The epidermis is the outermost cell layer of the primary plant body. In some older works the cells of the leaf epidermis have been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
