Citizendia

Stem showing internode and nodes plus leaf petiole and new stem rising from node.
Stem showing internode and nodes plus leaf petiole and new stem rising from node.

A stem is one of two main structural axes of a vascular plant. Vascular plants (also known as tracheophytes or higher plants) are those Plants that have lignified tissues for conducting The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence (flowers), cones or other stems etc. In Botany, a bud is an undeveloped or embryonic Shoot and normally occurs in the Axil of a Leaf or at the tip of the stem In Botany, a leaf is an above-ground Plant organ specialized for Photosynthesis. An inflorescence is a group or cluster of Flowers arranged on a stem that is composed of a main Branch or a complicated arrangement of branches A cone (in formal botanical usage Strobilus, plural strobili is an organ on Plants in the division Pinophyta ( Conifers The internodes act as spaces that distance one node from another. The term shoots is often confused with stems; shoots generally refer to new fresh plant growth and does include stems but also to other structures like leaves or flowers. Shoots are new plant growth they can include stems, flowering stems with flower buds leaves The other main structural axis of plants is the root. ROOT is an object-oriented program and library developed by CERN. In most plants stems are located above the soil surface but some plants have underground stems. Underground stems are modified plant structures that derive from stem tissue but exist under the Soil surface

Stems have four main functions which are:[1]

Contents

Specialized terms for stems

Stem showing internode and nodes plus leaf petioles.
Stem showing internode and nodes plus leaf petioles.

Stems are often specialized for storage, asexual reproduction, protection or photosynthesis, including the following:

Stem structure

Flax stem cross-section, showing locations of underlying tissues. Ep = epidermis; C = cortex; BF = bast fibres; P = phloem; X = xylem; Pi = pith
Flax stem cross-section, showing locations of underlying tissues. Flax (also known as common flax or linseed) (binomial name Linum usitatissimum) is a member of the genus Linum Ep = epidermis; C = cortex; BF = bast fibres; P = phloem; X = xylem; Pi = pith
See also: Stele (biology)

Stem usually consist of three tissues, dermal tissue, ground tissue and vascular tissue. In Botany, the cortex is the outer of the stem or Root of a plant bounded on the outside by the epidermis and on the inside by the Endodermis Bast fibre ( fiber) or skin fibre is Plant fibre collected from the Phloem (the "inner bark" or the skin or bast surrounding In Vascular plants phloem is the living tissue that carries organic Nutrients (known as photosynthate particularly Sucrose, a sugar to In Vascular plants xylem is one of the two types of transport tissue Phloem being the other Pith is a light substance that is found in Vascular plants It consists of soft spongy Parenchyma cells and is located in the center of the stem. In a Vascular plant, the stele is the central part of the Root or stem containing the Vascular tissue and occasionally a Pith. The epidermis is the outer single-layered group of cells covering a Plant, especially the Leaf and young tissues of a Vascular plant including stems The types of ground tissue found in Plants develop from ground tissue Meristem and consists of three simple tissues Parenchyma (cells This is an article about vascular tissue in plants For transport in animals see Circulatory system. The dermal tissue covers the outer surface of the stem and usually functions to waterproof, protect and control gas exchange. The ground tissue usually consists mainly of parenchyma cells and fills in around the vascular tissue. It sometimes functions in photosynthesis. Vascular tissue provides long distance transport and structural support. Most or all ground tissue may be lost in woody stems. The dermal tissue of aquatic plants stems may lack the waterproofing found in aerial stems. The arrangement of the vascular tissues varies widely among plant species.

Dicot stems

Dicot stems with primary growth have pith in the center, with vascular bundles forming a distinct ring visible when the stem is viewed in cross section. Dicotyledons, or "dicots", is a name for a group of Flowering plants whose Seed typically has two embryonic leaves or Cotyledons There The outside of the stem is covered with an epidermis, which is covered by a waterproof cuticle. The epidermis also may contain stomata for gas exchange and hairs. In Botany, a stoma (also stomate; plural stomata) is a tiny opening or pore found mostly on the underside of a Plant Leaf A cortex of parenchyma cells lies between the epidermis and vascular bundles.

Woody dicots and many nonwoody dicots have secondary growth originating from their lateral or secondary meristems: the vascular cambium and the cork cambium or phellogen. In many Vascular plants, secondary growth is the result of the activity of the Vascular cambium. The vascular cambium is a Lateral meristem in the Vascular tissue of plants Cork cambium is a tissue found in many vascular plants as part of the Periderm. The vascular cambium forms between the xylem and phloem in the vascular bundles and connects to form a continuous cylinder. The vascular cambium cells divide to produce secondary xylem to the inside and secondary phloem to the outside. In Vascular plants xylem is one of the two types of transport tissue Phloem being the other In Vascular plants phloem is the living tissue that carries organic Nutrients (known as photosynthate particularly Sucrose, a sugar to As the stem increases in diameter due to production of secondary xylem and secondary phloem, the cortex and epidermis are eventually destroyed. Before the cortex is destroyed, a cork cambium develops there. The cork cambium divides to produce waterproof cork cells externally and sometimes phelloderm cells internally. Those three tissues form the periderm, which replaces the epidermis in function. Bark, also known as periderm is the outermost layer of stems and Roots of Woody plants such as Trees It overlays the Wood and consists Areas of loosely-packed cells in the periderm that function in gas exchange are called lenticels.

Secondary xylem is commercially important as wood. In Vascular plants xylem is one of the two types of transport tissue Phloem being the other Wood is hard fibrous lignified structural tissue produced as secondary Xylem in the stems of Woody plants notably trees but also shrubs The seasonal variation in growth from the vascular cambium is what creates yearly tree rings in temperate climates. The vascular cambium is a Lateral meristem in the Vascular tissue of plants Tree rings are the basis of dendrochronology, which dates wooden objects and associated artifacts. Dendrochronology (from Greek grc δένδρον dendron, "tree" grc χρόνος khronos, "time" and grc -λογία Dendroclimatology is the use of tree rings as a record of past climates. Dendroclimatology is the science of determining past Climates from Trees (primarily Tree rings) The aerial stem of an adult tree is called a trunk. A tree is a perennial Woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or In Botany, trunk (or bole) refers to the main structural member of a Tree that supports the Branches and is supported by and directly attached The dead, usually darker inner wood of a large diameter trunk is termed the heartwood. Wood is hard fibrous lignified structural tissue produced as secondary Xylem in the stems of Woody plants notably trees but also shrubs The outer, living wood is termed the sapwood. For the NATO reporting name for the R-7 Semyorka intercontinental ballistic missile see SS-6 Sapwood.

Monocot stems

The trunk of this redwood tree is its stem.
The trunk of this redwood tree is its stem. Sequoia sempervirens is the sole living Species of the Genus Sequoia in the cypress family Cupressaceae (formerly

Vascular bundles are present throughout the monocot stem, although concentrated towards the outside. Monocotyledons or monocots are one of two major groups of Flowering plants (angiosperms that are traditionally recognised the other being Dicotyledons This differs from the dicot stem that has a ring of vascular bundles and often none in the center. The shoot apex in monocot stems is more elongated. Leaf sheathes grow up around it, protecting it. This is true to some extent of almost all monocots. Monocots rarely produce secondary growth and are therefore seldom woody. However, many monocot stems increase in diameter via anamolous secondary growth. In many Vascular plants, secondary growth is the result of the activity of the Vascular cambium.

Gymnosperm stems

All gymnosperms are woody plants. Gymnosperm (Gymnospermae are a group of Spermatophyte seed-bearing Plants with Ovules on the edge or blade of an open Sporophyll, which are Their stems are similar in structure to woody dicots except that most gymnosperms produce only tracheids in their xylem, not the vessels found in dicots. Tracheids are elongated cells in the Xylem of Vascular plants serving in the transport of water and mineral salts Gymnosperm wood also often contains resin ducts. Resin, not to be confused with Rosin, is a Hydrocarbon Secretion of many Plants particularly coniferous trees. Woody dicots are called hardwoods, e. g. oak, maple and walnut. The term oak can be used as part of the common name of any of about 400 species of Trees and Shrubs in the Genus Quercus (from Latin Acer ( maple) is a Genus of Trees or Shrubs They are variously classified in a family of their own the Aceraceae, or Walnuts (genus Juglans) are Plants in the family Juglandaceae. In contrast, softwoods are gymnosperms, such as pine, spruce and fir. This article is about the tree For other uses of the term "pine" see Pine (disambiguation. Spruce refers to Trees of the genus Picea, a genus of about 35 species of Coniferous Evergreen trees in the Family Pinaceae Firs ( Abies) are a genus of between 45-55 species of Evergreen conifers in the family Pinaceae.

Tasmanian tree fern
Tasmanian tree fern

Fern stems

Most ferns have rhizomes with no vertical stem. A fern is any one of a group of about 20000 Species of Plants classified in the phylum or division Pteridophyta, also known as Filicophyta In Botany, a rhizome is a horizontal stem of a Plant that is usually found underground often sending out Roots and Shoots The exception is tree ferns, with vertical stems up to about 20 meters. The order Cyatheales is a Taxonomic division of the Fern subclass Cyatheatae, which includes the tree ferns. The stem anatomy of ferns is more complicated than that of dicots because fern stems often have one or more leaf gaps in cross section. A leaf gap is where the vascular tissue branches off to a frond. A frond is a large Leaf with many divisions to it and the term is typically used for the leaves of palms Ferns or Cycads A frond is In cross section, the vascular tissue does not form a complete cylinder where a leaf gap occurs. Fern stems may have solenosteles or dictyosteles or variations of them. In a Vascular plant, the stele is the central part of the Root or stem containing the Vascular tissue and occasionally a Pith. In a Vascular plant, the stele is the central part of the Root or stem containing the Vascular tissue and occasionally a Pith. Many fern stems have phloem tissue on both sides of the xylem in cross-section.

Economic importance

White and green asparagus - crispy stems are the edible parts of this vegetable
White and green asparagus - crispy stems are the edible parts of this vegetable

There are thousands of species whose stems have economic uses. Asparagus officinalis is a flowering plant species in the genus Asparagus from which the Vegetable known as asparagus is obtained Stems provide a few major staple crops such as potato and taro. The potato is a Starchy Tuberous crop Vegetable from the perennial Solanum tuberosum of the Solanaceae Taro (from Tahitian or other Polynesian languages) more rarely kalo (from Hawaiian) and gabi in The Philippines, is a Sugar cane stems are a major source of sugar. Sugarcane ( Saccharum) is a genus of 6 to 37 species (depending on taxonomic interpretation of tall perennial grasses (family Poaceae tribe Andropogoneae Maple sugar is obtained from trunks of maple trees. Maple sugar is what remains after the sap of the Sugar maple is boiled for longer than is needed to create Maple syrup or Maple taffy. Acer ( maple) is a Genus of Trees or Shrubs They are variously classified in a family of their own the Aceraceae, or Vegetables from stems are asparagus, bamboo shoots, cactus pads or nopalitos, kohlrabi, and water chestnut. The term " vegetable " generally means the edible parts of Plants The definition of the word is traditional rather than Scientific, however Asparagus officinalis is a flowering plant species in the genus Asparagus from which the Vegetable known as asparagus is obtained Bamboo shoots are the edible Shoots (new bamboo culms that come out of the ground of Bamboo species Bambusa vulgaris and Phyllostachys Nopalitos is a dish made with diced Nopales They are sold fresh bottled or canned and less often dried. Kohlrabi ( German Turnip) ( Brassica oleracea Gongylodes Group is a low stout Cultivar of the Cabbage that will grow almost anywhere The spice, cinnamon is bark from a tree trunk. Cinnamon ( Cinnamomum verum, synonym C zeylanicum) is a small Evergreen Tree 10–15 metres (32 Cellulose from tree trunks is a food additive in bread, grated Parmesan cheese, and other processed foods. Gum arabic is an important food additive obtained from the trunks of Acacia senegal trees. Gum arabic, a Natural gum also called gum acacia, and chaar gund or char goond (in India is the hardened Sap taken from two species la Acacia senegal is a small deciduous Acacia tree known by the common names Rudraksha, Gum Acacia, Gum Arabic Tree, or Chicle, the main ingredient in chewing gum, is obtained from trunks of the chicle tree. Chicle is the Natural gum from Manilkara chicle, which is a tropical evergreen tree native to Central America. For songs called "Chewing Gum" see Chewing Gum (song Chewing gum is a type of Confectionery traditionally made of Chicle

Medicines obtained from stems include quinine from the bark of cinchona trees, camphor distilled from wood of a tree in the same genus that provides cinnamon, and the muscle relaxant curare from the bark of tropical vines. Quinine (ˈkwaɪnaɪn kwɪˈniːn ˈkwiːniːn is a natural white Crystalline Alkaloid having Antipyretic (fever-reducing antimalarial, Cinchona is a Genus of about 25 Species in the family Rubiaceae, native to tropical South America. } Camphor is a waxy white or transparent solid with a strong aromatic odor Curare ''rah'' ree is a common name for various Arrow poisons originating from South America

Wood is a used in thousands of ways, e. Wood is hard fibrous lignified structural tissue produced as secondary Xylem in the stems of Woody plants notably trees but also shrubs g. buildings, furniture, boats, airplanes, wagons, car parts, musical instruments, sports equipment, railroad ties, utility poles, fence posts, pilings, toothpicks, matches, plywood, coffins, shingles, barrel staves, toys, tool handles, picture frames, veneer, charcoal and firewood. For other kinds of building materials see Hardware, Biology, Star formation. Furniture is the Mass noun for the movable objects which may support the human body (seating furniture and beds, provide storage or hold objects on horizontal A boat is a Watercraft of modest size designed to float or plane on water and provide transport over it Overview Fixed-wing aircraft range from small training and recreational aircraft to Wide-body aircraft and military cargo aircraft. A wagon (in British English, sometimes waggon) or dray is a heavy four-wheeled Vehicle. A musical instrument is a device constructed or modified for the purpose of making Music. Sports equipment is a general term for any object used for Sport or Exercise. A railroad tie, cross tie, or railway sleeper is a rectangular object used as a base for Railroad tracks. A utility pole, telegraph pole, telephone pole, power (electricity pole, or telegraph post is a Pole used to support overhead A toothpick is a small stick of Wood, Plastic, Bamboo, Metal or other substance used to remove detritus from the Teeth, usually after A match is a consumable Tool for lighting a Fire under controlled circumstances on demand Plywood is a type of Engineered board made from thin sheets of Wood, called plies or veneers A coffin (also known as a casket in North American English) is a funerary Box used in the display and containment of deceased remains – either for A shake is a wooden shingle that is made from split logs When these are used for covering the top of a house the result is a shake Roof. A barrel or cask is a hollow cylindrical container traditionally made of Wood Staves and bound with Iron Hoops The This article is about playthings For other uses of the term see Toy (disambiguation. A broader definition of a tool is an entity used to interface between two or more domains that facilitates more effective action of one domain upon the other A picture frame is a container added to a picture in order to enhance it make it easier to display or in some cases to protect it In Woodworking, veneer refers to thin slices of wood usually thinner than 3 mm (1/8 inch that are typically Glued onto core panels (typically Wood Charcoal' is the blackish residue consisting of impure Carbon obtained by removing water and other volatile constituents from Animal and Vegetation Firewood was the primary source of fuel until the 1800s when it was displaced by coal and later by oil Wood pulp is widely used to make paper, cardboard, cellulose sponges, cellophane and some important plastics and textiles, such as cellulose acetate and rayon. Wood pulp is a dry fibrous material prepared by chemically or mechanically separating the fibers which make up Wood. Paper is thin material mainly used for writing upon printing upon or packaging Cardboard is a generic non-specific term for a heavy duty Paper based product Cellulose is an Organic compound with the formula, a Polysaccharide consisting of a linear chain of several hundred to over ten thousand β(1→4 Cellophane is a thin transparent sheet made of regenerated Cellulose. Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products A textile is a flexible material comprised of a network of natural or artificial Fibres often referred to as thread or Yarn. Cellulose acetate, first prepared in 1865 is the Acetate Ester of Cellulose. Rayon is a manufactured regenerated cellulosic Fiber. Rayon is produced from naturally occurring Polymers and therefore it is not a truly Bamboo stems also have hundreds of uses, including paper, buildings, furniture, boats, musical instruments, fishing poles, water pipes, plant stakes, and scaffolding. Bamboo is a group of Woody perennial Evergreen Plants in the True grass family Poaceae, subfamily A fishing rod or a fishing pole is a Tool used to catch fish, usually in conjunction with the Sport of Angling, can also be used in For the various smoking devices see Hookah or Bong. For other uses see Pipe. Scaffolding is a temporary framework used to support people and material in the construction or repair of buildings and other large structures Trunks of palm trees and tree ferns are often used for building. Arecaceae or Palmae (also known by the name Palmaceae, which is taxonomically invalid or commonly palm tree) the palm family is a family of Flowering The order Cyatheales is a Taxonomic division of the Fern subclass Cyatheatae, which includes the tree ferns. Reed stems are also important building materials in some areas. Phragmites australis, the common reed, is a large perennial grass found in Wetlands throughout temperate and tropical regions of the

Tannins used for tanning leather are obtained from the wood of certain trees, such as quebracho. Tannins are Astringent, bitter plant Polyphenols that either bind and Precipitate or shrink Proteins The astringency from the tannins is what Leather is a material created through the Tanning of hides and Skins of Animals primarily Cattlehide The Tanning process For the left-wing Argentine group see Quebracho (group. For the monetary unit see Quebracho (money. Cork is obtained from the bark of the cork oak. Cork material is a Prime-subset of generic cork tissue, harvested for commercial use primarily from the Cork Oak tree Quercus The Cork Oak ( Quercus suber) is a medium-sized Evergreen Oak tree in the section ''Quercus'' sect Rubber is obtained from the trunks of Hevea brasiliensis. The Pará rubber tree ( Hevea brasiliensis) often simply called rubber tree, is a Tree belonging to the family Euphorbiaceae Rattan, used for furniture and baskets, is made from the stems of tropical vining palms. Rattan (from the Malay rotan) is the name for the roughly six hundred Species of palms in the tribe Calameae, native to tropical Bast fibers for textiles and rope are obtained from stems include flax, hemp, jute and ramie. Bast fibre ( fiber) or skin fibre is Plant fibre collected from the Phloem (the "inner bark" or the skin or bast surrounding Flax (also known as common flax or linseed) (binomial name Linum usitatissimum) is a member of the genus Linum This article is about the cultivation and uses of industrial hemp not its psychoactive cousin Cannabis (drug. Jute is a long soft shiny Vegetable fiber that can be spun into coarse strong threads Ramie ( Boehmeria nivea) is a Flowering plant in the Nettle family Urticaceae, native to eastern Asia. The earliest paper was obtained from the stems of papyrus by the ancient Egyptians. Papyrus (/pəˈpaɪrəs/ (Rhymes -aɪrəs)is a thick paper-like material produced from the Pith of the papyrus plant Cyperus papyrus

Amber is fossilized sap from tree trunks; it is used for jewelry and may contain ancient animals. Amber is Fossil tree Resin, which is appreciated for its color and beauty Jewellery (also spelled jewelry, see spelling differences) is a personal Ornament, such as a necklace ring or bracelet made from Gemstones Resins from conifer wood are used to produce turpentine and rosin. Turpentine (also called spirit of turpentine oil of turpentine wood turpentine gum turpentine is a fluid obtained by the Distillation of Resin obtained from trees Rosin, formerly called colophony or Greek pitch ( Pix græca) is a solid form of Resin obtained from Pines and some other Plants Tree bark is often used as a mulch and in growing media for container plants. In Agriculture and Gardening, '''mulch''' is a protective cover placed over the Soil, primarily to modify the effects of the local Climate.

Some ornamental plants are grown mainly for their attractive stems, e. g. :

References

  1. ^ Raven, Peter H. Betula papyrifera ( Paper Birch, also known as American White Birch and Canoe Birch) is a species of Birch native to northern Salix matsudana ( Chinese Willow) is a species of Willow native to northwestern China. The hazels ( Corylus) are a genus of Deciduous Trees and large Shrubs native to the temperate northern hemisphere Acer griseum ( Paperbark Maple;) is a species of Maple native to central China, in the provinces of Gansu, Henan, In general a reference is a relation between objects in which one object designates by linking to another object , Ray Franklin Evert, and Helena Curtis. 1981. Biology of plants. New York, N. Y. : Worth Publishers. ISBN 0-87901-132-7



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