CanadianKnights
Well-Known Member
Basic Botany Compilation
[Plant Anatomy & General Terms]
Adventitious Root - Adventitious roots arise out-of-sequence from the more usual root formation of branches of a primary root, and instead originate from the stem, branches, leaves, or old woody roots.
Aerial Root -Roots entirely above the ground, such as in ivy (Hedera) or in epiphytic orchids. They function as prop roots, as in maize or anchor roots or as the trunk in strangler fig.
Apical Dominance -In plant physiology, apical dominance is the phenomenon whereby the main central stem of the plant is dominant over (i.e., grows more strongly than) other side stems; on a branch the main stem of the branch is further dominant over its own side branchlets. The apical bud (or tip) produces the growth hormone auxin, which not only promotes cell division but also diffuses downwards and inhibits the development of lateral bud growth, which would otherwise compete with the apical tip for light and nutrients. Removing the apical tip and its suppressive hormone allows the lower dormant lateral buds to develop and the buds between the leaf stalk and stem to produce new shoots, which compete to become the lead growth. Manipulating this natural response to damage (known as the principle of apical dominance) by processes such as pruning (as well as coppicing and pollarding) allows the horticulturist to determine the shape, size, and productivity of many fruiting trees and bushes.
Axil - The angle between the upper side of the stem and a leaf, branch, bract, tubercle or petiole.
Axillary bud -The axillary bud is an embryonic shoot which lies at the junction of the stem and petiole of a plant.
Climacteric - Climacteric fruits refer to fruits that have high respiration rate during the fruit's ripening. During the ripening process of climacteric fruits, the production of a phytohormone, ethylene, dramatically increase up to 1000-fold of the basal ethylene level. Climacteric fruits are ones that are able to ripen after being picked. An example of climacteric fruits is bananas; they are picked and shipped green and then ripen at a later time (often in the store or home). Climacteric fruits include, but are not limited to, apples, apricots, avocados, bananas, cantaloupes, figs, guavas, kiwis, mangoes, nectarines, peaches, pears, persimmons, plums, and tomatoes.
Etiolation - A process in flowering plants grown in partial or complete absence of light. It is characterized by long, weak stems; smaller, sparser leaves due to longer internodes; and a pale yellow color (chlorosis). It increases the likelihood that a plant will reach a light source, often from under the soil, leaf litter, or shade from competing plants. The growing tips are strongly attracted to light and will elongate towards it. The pale color results from a lack of chlorophyll; by not producing chlorophyll in the dark when it could not function, the plant allocates its resources to growth.
Fibrous Roots -The opposite of a taproot system. It is usually formed by thin, moderately branching roots growing from the stem. A fibrous root system is universal in monocotyledonous plants and ferns.
Geotropism (Gravitropism) - A turning or growth movement by a plant or fungus in response to gravity. Charles Darwin was one of the first to scientifically document that roots show positive gravitropism and stems show negative gravitropism. That is, roots grow in the direction of gravitational pull (i.e., downward) and stems grow in the opposite direction (i.e., upwards). This behavior can be easily demonstrated with a potted plant. When laid onto its side, the growing parts of the stem begin to display negative gravitropism, bending (biologists say, turning; see tropism) upwards. Herbaceous (non-woody) stems are capable of a small degree of actual bending, but most of the redirected movement occurs as a consequence of root or stem growth in a new direction.
Inter Node - A segment of a stem between two nodes
Meristem - A meristem is the tissue in most plants consisting of undifferentiated cells (meristematic cells), found in zones of the plant where growth can take place. The meristematic cells give rise to various organs of the plant, and keep the plant growing. The Shoot Apical Meristem (SAM) gives rise to organs like the leaves and flowers. The cells of the apical meristems - SAM and RAM (Root Apical Meristem)- divide rapidly and are considered to be indeterminate, in that they do not possess any defined end fate. In that sense, the meristematic cells are frequently compared to the stem cells in animals, that have an analogous behavior and function.
Node -The place on a plant stem where a leaf is attached
Pedicel -A stem that attaches single flowers to the main stem of the inflorescence. It is the branches or stalks that hold each flower in an inflorescence that contains more than one flower.
Peduncle - The stem or branch that holds a group of pedicels
Petiole - The stalk of a leaf, attaching the blade to the stem
Phloem - In vascular plants, phloem is the living tissue that carries organic nutrients (known as photosynthate), in particular, glucose, a sugar, to all parts of the plant where needed. In trees, the phloem is the innermost layer of the bark, hence the name, derived from the Greek word φλόος (phloos) "bark". The phloem is concerned mainly with the transport of soluble organic material made during photosynthesis. This is called translocation.
Photoperiod - Photoperiodicity is the physiological reaction of organisms to the length of day or night. It occurs in plants and animals.
Phototropism - Directional growth in which the direction of growth is determined by the direction of the light source. In other words, it is the growth and response to a light stimulus. Phototropism is most often observed in plants, but can also occur in other organisms such as fungi. The cells on the plant that are farthest from the light have a chemical called auxin that reacts when phototropism occurs. This causes the plant to have elongatedcells on the farthest side from the light. Phototropism is one of the many plant tropisms or movements which respond to external stimuli. Growth towards a light source is a positivephototropism, while growth away from light is called negativephototropism (or Skototropism). Most plant shoots exhibit positive phototropism, while roots usually exhibit negative phototropism, although gravitropism may play a larger role in root behavior and growth. Some vine shoot tips exhibit negative phototropism, which allows them to grow towards dark, solid objects and climb them.
Sessile -A characteristic of plants whose flowers or leaves are borne directly from the stem
Stomata - In botany, a stoma (also stomate; plural stomata) is a pore, found in the leaf and stem epidermis that is used for gas exchange. The pore is bordered by a pair of specialized parenchyma cells known as guard cells which are responsible for regulating the size of the opening. The term stoma is also used collectively to refer to an entire stomatal complex, both the pore itself and its accompanying guard cells. Air containing carbon dioxide and oxygen enters the plant through these openings where it is used in photosynthesis and respiration, respectively. Oxygen produced by photosynthesis in the spongylayer cells (parenchyma cells with pectin) of the leaf interior exits through these same openings. Also, water vapor is released into the atmosphere through these pores in a process called transpiration.
Tap Root - A taproot is an enlarged, somewhat straight to tapering plant root that grows vertically downward. It forms a center from which other roots sprout laterally.
Xylem - In vascular plants, xylem is one of the two types of transport tissue, phloem being the other. The word "xylem" is derived from classical Greek ξυλον (xylon), "wood", and indeed the best-known xylem tissue is wood, though it is found throughout the plant. Its basic function is to transport water but it also transports some nutrients through the plant.
[Environment]
Cold Stratification - In horticulture, stratification is the process of pretreating seeds to simulate natural winter conditions that a seed must endure before germination. Many seed species undergo an embryonic dormancy phase, and generally will not sprout until this dormancy is broken. The time taken to stratify seeds depends on species and conditions; though in many cases two months is sufficient.
Hardiness-Hardiness of plants describe their ability to survive adverse growing conditions. It is usually limited to discussions of climatic adversity. Thus a plant's ability to tolerate cold, heat, drought, flooding, or wind are typically considered measurements of hardiness. Hardiness of plants is defined by their native extent's geographic location: longitude, latitude and elevation. These attributes are often simplified to a hardiness zone. In temperate latitudes, the term most often describes resistance to cold, or "cold-hardiness," and is generally measured by the lowest temperature a plant can withstand. Hardiness of a plant is usually divided into three categories: tender, half-hardy, and hardy. Tender plants are those killed by freezing temperatures, while hardy plants survive freezing—at least down to certain temperatures, depending on the plant. Plants vary a lot in their tolerance of growing conditions. The selective breeding of varieties capable of withstanding particular climates forms an important part of agriculture and horticulture. Plants adapt to changes in climate on their own to some extent. Part of the work of nursery growers of plants consists of cold hardening, or hardening off their plants, to prepare them for likely conditions in later life.
[Soil & Growth Mediums]
Coconut Fiber -Coir is a natural fibre extracted from the husk of coconut and used in products such as floor mats, doormats, brushes, mattresses etc. Technically coir is the fibrous material found between the hard, internal shell and the outer coat of a coconut. Other uses of brown coir (made from ripe coconut) are in upholstery padding, sacking and horticulture. White coir is harvested from unripe coconuts, and is used for making finer brushes, string, rope and fishing nets.
Mineralwool - Mineralwool, mineral fibres or man-made mineral fibres are fibres made from natural or synthetic minerals or metal oxides. The latter term is generally used to refer solely to synthetic materials including fibreglass, ceramic fibres and rock or stone wool. Industrial applications of mineral wool include thermal insulation, filtration, soundproofing, and germination of seedlings.
Humus-In soil science, humus refers to any organic matter that has reached a point of stability, where it will break down no further and might, if conditions do not change, remain as it is for centuries, if not millennia. In agriculture, humus is sometimes also used to describe mature compost, or natural compost extracted from a forest or other spontaneous source for use to amend soil. It is also used to describe a topsoil horizon that contains organic matter (humus type, humus form, humus profile).
Perlite -Perlite is an amorphous volcanic glass that has a relatively high water content, typically formed by the hydration of obsidian. It occurs naturally and has the unusual property of greatly expanding when heated sufficiently. It is an industrial mineral and a commercial product useful for its light weight after processing.
Silt - Silt is granular material of a size somewhere between sand and clay derived from soil or rock. Silt may occur as a soil or as suspended sediment (also known as suspended load) in a surface water body. It may also exist as soil deposited at the bottom of a water body.
Vermiculite - Vermiculite is a natural mineral that expands with the application of heat. The expansion process is called exfoliation and it is routinely accomplished in purpose-designed commercial furnaces. Vermiculite is formed by weathering or hydrothermal alteration of biotite or phlogopite. Large commercial vermiculite mines currently exist in Russia, South Africa, China, and Brazil.
[Nutrients]
Macronutrients- Macronutrients can be broken into two more groups:
primary and secondarynutrients.
Primary Nutrients - Nitrogen(N), phosphorus(P), and potassium(K). These major nutrients usually are lacking from the soil first because plants use large amounts for their growth and survival.
Secondary Nutrients - Calcium(Ca), magnesium(Mg), and sulfur(S). There are usually enough of these nutrients in the soil so fertilization is not always needed. Also, large amounts of Calcium and Magnesium are added when lime is applied to acidic soils. Sulfur is usually found in sufficient amounts from the slow decomposition of soil organic matter, an important reason for not throwing out grass clippings and leaves.
Micronutrients - Micronutrients are those elements essential for plant growth which are needed in only very small (micro) quantities . These elements are sometimes called minor elements or trace elements, but use of the term micronutrient is encouraged by the American Society of Agronomy and the Soil Science Society of America. The micronutrients are boron(B), copper(Cu), iron(Fe), chloride(Cl), manganese(Mn), molybdenum (Mo)and zinc(Zn). Recycling organic matter such as grass clippings and tree leaves is an excellent way of providing micronutrients (as well as macronutrients) to growing plants.
[Cultivation Methods]
Hydroponic - Hydroponics is a method of growing plants using mineral nutrient solutions, in water, without soil. Terrestrial plants may be grown with their roots in the mineral nutrient solution only or in an inert medium, such as perlite, gravel, mineral wool, or coconut husk. Researchers discovered in the 19th century that plants absorb essential mineral nutrients as inorganic ions in water. In natural conditions, soil acts as a mineral nutrient reservoir but the soil itself is not essential to plant growth. When the mineral nutrients in the soil dissolve in water, plant roots are able to absorb them. When the required mineral nutrients are introduced into a plant's water supply artificially, soil is no longer required for the plant to thrive. Almost any terrestrial plant will grow with hydroponics. Hydroponics is also a standard technique in biology research and teaching.
Organic/Soil - Soil is a natural body consisting of layers (soil horizons) of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics. It's composed of particles of broken rock that have been altered by chemical and environmental processes that include weathering and erosion. Soil differs from its parent rock due to interactions between the lithosphere, hydrosphere, atmosphere, and the biosphere. It is a mixture of mineral and organic constituents that are in solid, gaseous and aqueous states.
[Plant Hormones and Growth Regulators]
Hormones - Plant hormones (also known as phytohormones) are chemicals that regulate plant growth, which, in the UK, are termed 'plant growth substances'. Plant hormones are signal molecules produced within the plant, and occur in extremely low concentrations. Hormones regulate cellular processes in targeted cells locally and when moved to other locations, in other locations of the plant. Hormones also determine the formation of flowers, stems, leaves, the shedding of leaves, and the development and ripening of fruit. Plants, unlike animals, lack glands that produce and secrete hormones, instead each cell is capable of producing hormones. Plant hormones shape the plant, affecting seed growth, time of flowering, the sex of flowers, senescence of leaves and fruits. They affect which tissues grow upward and which grow downward, leaf formation and stem growth, fruit development and ripening, plant longevity, and even plant death. Hormones are vital to plant growth and lacking them, plants would be mostly a mass of undifferentiated cells. They includeAbscisic acid, Auxins, Cytokinins, Ethylene, Gibberellins, Brassinosteroids, Salicylic acid, Jasmonates, Plant peptide hormones, Polyamines, Nitric oxide, Strigolactones, and Karrikins.
Abscisic acid -Induces stomatal closure, decreasing transpiration to prevent water loss, Inhibits fruit ripening, Responsible for seed dormancy by inhibiting cell growth, inhibits seed germination, Inhibits the synthesis of Kinetin nucleotide, Downregulates enzymes needed for photosynthesis.
Auxins - Auxin stimulates cell elongation by stimulating wall loosening factors, such as elastins, to loosen cell walls.
The effect is stronger if gibberellins are also present. Auxin also stimulates cell division if cytokinins are present. When auxin and cytokinin are applied to callus, rooting can be generated if the auxin concentration is higher than cytokinin concentration. Xylem tissues can be generated when the auxin concentration is equal to the cytokinins. Auxin participates in phototropism, geotropism, hydrotropism and other developmental changes. The uneven distribution of auxin, due to environmental cues such as unidirectional light or gravity force, results in uneven plant tissue growth. Auxin also induces sugar and mineral accumulation at the site of application.
Cytokinins - Because cytokinin promotes plant cell division and growth, it is commercially utilized by produce farmers to increase the yield of a crop. A study showed a 5-10% increase in cotton yield under drought conditions when cytokinin was applied to the seedlings. Kinetin is the most important agent from the cytokinin group. Many experiments were done by the scientists on the effect of Cytokinin on plant physiology. As mentioned above, it increases the cell division, have effects on the initiation and development of root, helps in breaking bud dormancy.
Ethylene - Ethylene production is regulated by a variety of developmental and environmental factors. During the life of the plant, ethylene production is induced during certain stages of growth such as germination, ripening of fruits, abscission of leaves, and senescence of flowers. Ethylene production can also be induced by a variety of external aspects such as mechanical wounding, environmental stresses, and certain chemicals including auxin and other regulators
Gibberellins - Regulate growth and influence various developmental processes, including stem elongation, germination, dormancy, flowering, sex expression, enzyme induction, and leaf and fruit senescence
Brassinosteroids - A class of polyhydroxysteroids that have been recognized as a sixth class of plant hormones. These were first explored nearly forty years ago when Mitchell et al. reported promotion in stem elongation and cell division by the treatment of organic extracts of rapeseed (Brassica napus) pollen. Brassinolide was the first isolated brassinosteroid in 1979 when it was shown that pollen from Brassica napus could promote stem elongation and cell divisions, and the biologically active molecule was isolated. The yield of brassinosteriods from 230 kg of Brassica napus pollen was only 10 mg. Since their discovery, over 70 BR compounds have been isolated from plants.
Salicylic acid - Salicylic acid is known for its ability to ease aches and pains and reduce fevers. These medicinal properties, particularly fever relief, have been known since ancient times, and it was used as an anti-inflammatory drug. Some researchers believe that salicylate is an essential micronutrient in the human diet, potentially qualifying as a vitamin, namely Vitamin S
Jasmonates - The perception and downstream signaling of jasmonates is similar to that of the plant hormone auxin and uses the ubiquitin system. Jasmonic acid can be conjugated to the amino acid isoleucine. The resulting (+)-7-iso-Jasmonoyl-L-isoleucine (JA-Ile) is the bioactive jasmonate and forms a molecular glue between the protein COI1 and a JAZ protein
Polyamines - The polyamines, e.g. putrescine, spermidine, and spermine, constitute a group of cell components that are important in the regulation of cell proliferation and cell differentiation. There is also evidence suggesting a role for polyamines in programmed cell death. The figure below summarizes the metabolism and functions of polyamines.
Strigolactones - Implicated in inhibition of shoot branching. Strigolactones are carotenoid-derived and trigger germination of parasitic plant seeds (for example Striga from which they gained their name) and stimulate symbiotic mycorrhizal fungi.[3] Strigolactones contain a labile ether bond that is easily hydrolyzed in the rhizosphere meaning that there is a large concentration gradient between areas near the root and those further away.
Karrikins - A group of plant growth regulators found in the smoke of burning plant material. For many years scientists have known that smoke from forest fires had the ability to stimulate the germination of seeds. In 2004, after studying the thousands of chemical compounds found in smoke, it was discovered that a series of butenolides were responsible for this effect.
[Propagation and Reproduction]
Seed - A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant. The formation of the seed completes the process of reproduction in seed plants (started with the development of flowers and pollination), with the embryo developed from the zygote and the seed coat from the integuments of the ovule. Seeds have been an important development in the reproduction and spread of flowering plants, relative to more primitive plants like mosses, ferns and liverworts, which do not have seeds and use other means to propagate themselves. This can be seen by the success of seed plants (both gymnosperms and angiosperms) in dominating biological niches on land, from forests to grasslands both in hot and cold climates.
Clone (Vegetative Reproduction) -Vegetative reproduction (vegetative propagation, vegetative multiplication, vegetative cloning) is a form of asexual reproduction in plants. It is a process by which new individuals arise without production of seeds or spores. It can occur naturally or be induced by horticulturists. Although most plants normally reproduce sexually, many have the ability for vegetative propagation, or can be vegetatively propagated if small pieces are subjected to chemical (hormonal) treatments. This is because meristematic cells that are capable of differentiating are present in many plant tissues. Horticulturalists are interested in understanding how meristematic cells can be induced to reproduce an entire plant. Success rates and difficulty of propagation vary greatly. For example willow and coleus can be propagated merely by inserting a stem in water or moist soil. On the other hand, monocotyledons, unlike dicotyledons, typically lack a vascular cambium and therefore are harder to propagate.
Stolon - In biology, stolons are horizontal connections between organisms. They may be part of the organism, or of its skeleton; typically, animal stolons are external skeletons.
Rhizome - In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes. Rhizomes may also be referred to as creeping rootstalks or rootstocks.
[Pests & Disease]
Aphids -Also known as plant lice and in Britain and the Commonwealth as greenflies, blackflies or whiteflies, are small sap sucking insects, and members of the superfamily Aphidoidea. Aphids are among the most destructive insect pests on cultivated plants in temperate regions. The damage they do to plants has made them enemies of farmers and gardeners the world over, but from a zoological standpoint they are a very successful group of organisms. Their success is in part due to the asexual reproduction capability of some species.
Anthracnose - Generally found in the eastern part of the U.S., anthracnose infected plants develop dark lesions on stems, leaves or fruit. These lesions often become covered with pink spore masses. Dieback often occurs.
Bacterial Leaf Spot - Infected plants have water soaked spots, sometimes with a yellow halo, usually uniform in size. The spots enlarge and will run together under wet conditions. Under dry conditions the spots have a speckled appearance.
Caterpillar - Caterpillars are voracious feeders and many of them are considered pests in agriculture. Many moth species are better known in their caterpillar stages because of the damage they cause to fruits and other agricultural produce.
Downy Mildew - Downy mildew appears on the upper leaf surface as pale green or yellow spots. The spots look slightly gray and fuzzy when viewed from below, especially during periods of high relative humidity.
Fungi -The majority of phytopathogenic fungi belong to the Ascomycetes and the Basidiomycetes. The fungi reproduce both sexually and asexually via the production of spores. These spores may be spread long distances by air or water, or they may be soil borne. Many soil borne spores, normally zoospores, are capable of living saprotrophically, carrying out the first part of their lifecycle in the soil. Fungal diseases can be controlled through the use of fungicides in agriculture, however new races of fungi often evolve that are resistant to various fungicides.
Gray Mold-Gray mold first appears as a white growth on the plant but very soon darkens to a gray color. Smoky-gray "dusty" spores form and are spread by the wind or in water. It is found everywhere plants are grown.
Rust - Common rust first appears as yellow spots on the leaves. The spots develop into oval reddish-brown and elevated lesions that contain a powdery mass of orange-red spores. Damage is most abundant on the leaves.
Slugs - Many slug species play an important ecosystem role by eating dead leaves, fungus, and decaying vegetable material. Other species eat parts of living plants. Some slugs are predators and eat other slugs and snails, or earthworms. Most carnivorous slugs on occasion also eat carrion, including dead of their own kind.
Spider Mites - Spider mites are members of the Acari (mite) family Tetranychidae, which includes about 1,600 species. They generally live on the under sides of leaves of plants, where they may spin protective silk webs, and they can cause damage by puncturing the plant cells to feed. Spider mites are known to feed on several hundred species of plant.
Verticillium Wilt - Verticillium wilt affects a broad array of plant species across the U.S. Yellow blotches on the lower leaves may be the first symptoms, then brown veins appear, and finally chocolate brown dead spots.
