The term "shoots" is often confused with "stems"; "shoots" generally refers to new fresh plant growth including both stems and other structures like leaves or flowers. In most plants stems are located above the soil surface but some plants have underground stems.
Stems have four main functions which are:
Stems have two pipe-like tissues called xylem and phloem. The xylem tissue transports water by the action of transpiration pull, capillary action and root pressure. The phloem tissue consists of sieve tubes and their companion cells. The two tissues are separated by cambium which is a tissue that divides to form xylem or phloem cells.
Stems are often specialized for storage, asexual reproduction, protection or photosynthesis, including the following:
Stem usually consist of three tissues, dermal tissue, ground tissue and vascular tissue. 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 with primary growth have pith in the center, with vascular bundles forming a distinct ring visible when the stem is viewed in cross section. 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 multicellular stem hairs called trichomes. A cortex consisting of hypodermis (collenchyma cells) and endodermis (starch containing cells) is present above the pericycle 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. 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. 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. Areas of loosely packed cells in the periderm that function in gas exchange are called lenticels.
Secondary xylem is commercially important as wood. The seasonal variation in growth from the vascular cambium is what creates yearly tree rings in temperate climates. Tree rings are the basis of dendrochronology, which dates wooden objects and associated artifacts. Dendroclimatology is the use of tree rings as a record of past climates. The aerial stem of an adult tree is called a trunk. The dead, usually darker inner wood of a large diameter trunk is termed the heartwood and is the result of tylosis. The outer, living wood is termed the sapwood.
Vascular bundles are present throughout the monocot stem, although concentrated towards the outside. 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, with Palms and Bamboo being notable exceptions. However, many monocot stems increase in diameter via anomalous secondary growth.
All gymnosperms are woody plants. 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. Gymnosperm wood also often contains resin ducts. Woody dicots are called hardwoods, e.g. oak, maple and walnut. In contrast, softwoods are gymnosperms, such as pine, spruce and fir.
Most ferns have rhizomes with no vertical stem. The exception is tree ferns, with vertical stems up to about 20 metres. 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. 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. Many fern stems have phloem tissue on both sides of the xylem in cross-section.
Foreign chemicals such as air pollutants, herbicides and pesticides can damage stem structures.
There are thousands of species whose stems have economic uses. Stems provide a few major staple crops such as potato and taro. Sugarcane stems are a major source of sugar. Maple sugar is obtained from trunks of maple trees. Vegetables from stems are asparagus, bamboo shoots, cactus pads or nopalitos, kohlrabi, and water chestnut. The spice, cinnamon is bark from a tree trunk. Gum arabic is an important food additive obtained from the trunks of Acacia senegal trees. Chicle, the main ingredient in chewing gum, is obtained from trunks of the chicle tree.
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.
Wood is used in thousands of ways, e.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. Wood pulp is widely used to make paper, paperboard, cellulose sponges, cellophane and some important plastics and textiles, such as cellulose acetate and rayon. Bamboo stems also have hundreds of uses, including paper, buildings, furniture, boats, musical instruments, fishing poles, water pipes, plant stakes, and scaffolding. Trunks of palm trees and tree ferns are often used for building. Stems of Reed are an important building material for use in thatching in some areas.
Tannins used for tanning leather are obtained from the wood of certain trees, such as quebracho. Cork is obtained from the bark of the cork oak. Rubber is obtained from the trunks of Hevea brasiliensis. Rattan, used for furniture and baskets, is made from the stems of tropical vining palms. Bast fibers for textiles and rope are obtained from stems include flax, hemp, jute and ramie. The earliest paper was obtained from the stems of papyrus by the ancient Egyptians.
Amber is fossilized sap from tree trunks; it is used for jewelry and may contain ancient animals. Resins from conifer wood are used to produce turpentine and rosin. Tree bark is often used as a mulch and in growing media for container plants. It also can become the natural habitat of lichens.
Some ornamental plants are grown mainly for their attractive stems, e.g.:
Apophysis may refer to:
A bony tubercle (anatomy)
Apophysis (spider), an outgrowth of the exoskeleton in spiders and other arachnids
In botany, an outgrowth or enlargement of an organ such as a plant stem
Apophysis (software), a fractal flame generating program for Microsoft Windows
Apophysis (geology), a discordant offshoot from another body, suchas a sill, dike, or plutonColeophora maritimella
Coleophora maritimella is a moth of the family Coleophoridae. It is found in Tunisia, Ireland, Great Britain, the Netherlands, Germany, Denmark, Sweden, France, Spain, Portugal, Italy, Sardinia, Sicily, Croatia, Albania, Greece, Bulgaria, Crete and Cyprus.
The wingspan is 9–11 mm. Head whitish-brown. Antennae white, ringed with fuscous. Forewings light brownish, with a few darker scales ; costa whitish from base to 2/3 ; veins indistinctly marked with whitish lines. Hindwings grey Only reliably identified by dissection and microscopic examination of the genitalia.
Adults are on wing from late June to early August.The larvae feed on the seedheads of Juncus maritimus and Juncus acutus. The larval case is made from a hollowed seed of the food plant. Larvae can be found from September to May. Pupation takes place in May and June on a plant stem.Corm
A corm, bulbo-tuber, or bulbotuber is a short, vertical, swollen underground plant stem that serves as a storage organ that some plants use to survive winter or other adverse conditions such as summer drought and heat (perennation).
The word cormous usually means plants that grow from corms, parallel to the terms tuberous and bulbous to describe plants growing from tubers and bulbs.Edible plant stem
Edible plant stems are one part of plants that are eaten by humans. Most plants are made up of stems, roots, leaves, flowers, and produce fruits containing seeds. Humans most commonly eat the seeds (e.g. maize, wheat), fruit (e.g. tomato, avocado, banana), flowers (e.g. broccoli), leaves (e.g. lettuce, spinach, and cabbage), roots (e.g. carrots, beets), and stems (e.g. asparagus, ginger) of many plants. There are also a few edible petioles (also known as leaf stems) such as celery or rhubarb.
Plant stems have a variety of functions. Stems support the entire plant and have buds, leaves, flowers, and fruits. Stems are also a vital connection between leaves and roots. They conduct water and mineral nutrients through xylem tissue from roots upward, and organic compounds and some mineral nutrients through phloem tissue in any direction within the plant. Apical meristems, located at the shoot tip and axillary buds on the stem, allow plants to increase in length, surface, and mass. In some plants, such as cactus, stems are specialized for photosynthesis and water storage.Hellinsia kellicottii
Hellinsia kellicottii (goldenrod borer) is a moth of the family Pterophoridae. It is found in eastern North America, from Massachusetts and New York, south to southern Florida and west to Colorado and Utah. It has also been recorded from Quebec, British Columbia, Arkansas and Wisconsin.
The wingspan is 14–29 mm. Adults are on wing as early as February in Florida and as late as October in New York. There is one generation per year.
The larvae feed on Solidago species. Young larvae bore into the stem. Before reaching the third instar, the larvae leave the upper part of the plant stem through a lateral hole and move down to the mature, wider stem. Here it makes another hole and bores down toward the roots.Internode
Internode may refer to:
Internode (botany), a portion of a plant stem between nodes
Internode (ISP), an Internet service provider in Australia
Internodal segment, a portion of a nerve fibreLeaflet (botany)
A leaflet (occasionally called foliole) in botany is a leaf-like part of a compound leaf. Though it resembles an entire leaf, a leaflet is not borne on a main plant stem or branch, as a leaf is, but rather on a petiole or a branch of the leaf. Compound leaves are common in many plant families and they differ widely in morphology. The two main classes of compound leaf morphology are palmate and pinnate.
For example, a hemp plant has palmate compound leaves, whereas some species of Acacia have pinnate leaves.
The ultimate free division (or leaflet) of a compound leaf, or a pinnate subdivision of a multipinnate leaf is called a pinnule or pinnula.Lignotuber
A lignotuber is a woody swelling of the root crown possessed by some plants as a protection against destruction of the plant stem, such as by fire. The crown contains buds from which new stems may sprout, as well as stores of starch that can support a period of growth in the absence of photosynthesis. The term "lignotuber" was coined in 1924 by Australian botanist Leslie R. Kerr.
Plants possessing lignotubers include Eucalyptus marginata (Jarrah), Eucalyptus brevifolia (snappy gum) and Eucalyptus ficifolia (scarlet gum) all of which can have lignotubers ten feet (3 meters) wide and three feet (one meter) deep as well as most mallees, and many Banksia species. Lignotubers develop from the cotyledonary bud in seedlings of several oak species including cork oak Quercus suber, but do not develop in several other oak species, and are not apparent in mature cork oak trees.The largest known lignotubers (also called "root collar burls") are those of the Coast Redwood (Sequoia sempervirens) of central and northern California and extreme southwestern Oregon. A lignotuber washed into Big Lagoon (30 miles (48 km) north of Eureka, California) by the full gale storm of 1977 was 41 feet (12.5 meters) in diameter and about half as tall and estimated to weigh 525 short tons (476.3 metric tonnes). The largest dicot lignotubers are those of the Chinese Camphor Tree, or Kusu (Cinnamomum camphora) of Japan, China and the Koreas. Ones at the Vergelegan Estate in Cape Town, South Africa which were planted in the late 1600s have muffin-shaped lignotubers up to six feet (2 meters) high and about thirty feet (9 meters) in diameter. Perhaps the largest lignotuber in Australia would be that of "Old Bottle Butt", a Red Bloodwood Tree (Corymbia gummifera) near Wauchope, New South Wales which has a lignotuber about eight feet (2.5 meters) in height, and seventeen feet thick (16.3 meters circumference) at breast height. Many plants with lignotubers grow in a shrubby habit, but with multiple stems arising from the lignotuber. The term lignotuberous shrub is used to describe this habit.List of root vegetables
Root vegetables are underground plant parts eaten by humans as food. Although botany distinguishes true roots (such as taproots and tuberous roots) from non-roots (such as bulbs, corms, rhizomes, and tubers, although some contain both hypocotyl and taproot tissue), the term "root vegetable" is applied to all these types in agricultural and culinary usage.Root vegetables are generally storage organs, enlarged to store energy in the form of carbohydrates. They differ in the concentration and the balance among starches, sugars, and other types of carbohydrate. Of particular economic importance are those with a high carbohydrate concentration in the form of starch; starchy root vegetables are important staple foods, particularly in tropical regions, overshadowing cereals throughout much of Central Africa, West Africa and Oceania, where they are used directly or mashed to make fufu or poi.
Many root vegetables keep well in root cellars, lasting several months. This is one way of storing food for use long after harvest, which is especially important in nontropical latitudes, where winter is traditionally a time of little to no harvesting. There are also season extension methods that can extend the harvest throughout the winter, mostly through the use of polytunnels.
Adherents of Jainism do not eat root vegetables.Lolium temulentum
Lolium temulentum, typically known as darnel, poison darnel, darnel ryegrass or cockle, is an annual plant of the genus Lolium within the family Poaceae. The plant stem can grow up to one meter tall, with inflorescence in the ears and purple grain. It has a global distribution.Parenchyma
Parenchyma () is the bulk of a substance. In animals, a parenchyma comprises the functional parts of an organ and in plants parenchyma is the ground tissue of nonwoody structures.Petiole (botany)
In botany, the petiole () is the stalk that attaches the leaf blade to the stem. Outgrowths appearing on each side of the petiole in some species are called stipules. Leaves lacking a petiole are called sessile or epetiolate.Phyllotaxis
In botany, phyllotaxis or phyllotaxy is the arrangement of leaves on a plant stem (from Ancient Greek phýllon "leaf" and táxis "arrangement"). Phyllotactic spirals form a distinctive class of patterns in nature.
The term was coined by Charles Bonnet to describe the arrangement of leaves on a plant.Plant stem cell
Plant stem cells are innately undifferentiated cells located in the meristems of plants. Plant stem cells serve as the origin of plant vitality, as they maintain themselves while providing a steady supply of precursor cells to form differentiated tissues and organs in plants. Two distinct areas of stem cells are recognised: the apical meristem and the lateral meristem.
Plant stem cells are characterized by two distinctive properties, which are: the ability to create all differentiated cell types and the ability to self-renew such that the number of stem cells is maintained. Plant stem cells never undergo aging process but immortally give rise to new specialized and unspecialized cells, and they have the potential to grow into any organ, tissue, or cell in the body. Thus they are totipotent cells equipped with regenerative powers that facilitate plant growth and production of new organs throughout lifetime.Unlike animals, plants are immobile. As plants cannot escape from danger by taking motion, they need a special mechanism to withstand various and sometimes unforeseen environmental stress. Here, what empowers them to withstand harsh external influence and preserve life is stem cells. In fact, plants comprise the oldest and the largest living organisms on earth, including Bristlecone Pines in California, U.S. (4,842 years old), and the Giant Sequoia in mountainous regions of California, U.S. (87 meters in height and 2,000 tons in weight). This is possible because they have a modular body plan that enables them to survive substantial damage by initiating continuous and repetitive formation of new structures and organs such as leaves and flowers.Plant stem cells are also characterized by their location in specialized structures called meristematic tissues, which are located in root apical meristem (RAM), shoot apical meristem (SAM), and vascular system ((pro)cambium or vascular meristem.)Poi (food)
Poi is primarily the traditional staple food in native cuisine of Hawaii, made from the underground plant stem (corm) of taro (known in Hawaiian as kalo).
Traditional poi is produced by mashing the cooked corm (baked or steamed) on a papa ku‘i ‘ai, a wooden pounding board, with a pōhaku ku‘i ‘ai, a carved basalt pestle. Modern methods use an industrial food processor to produce large quantities for retail distribution. Freshly pounded taro without the addition of water is called pa‘i ‘ai and is highly starchy and dough-like. Water is added to the pa‘i ‘ai during mashing, and again just before eating, to achieve the desired consistency, which can range from highly viscous to liquid. As such, poi can be classified as "one-finger", "two-finger", or "three-finger" depending on the consistency, alluding to how many fingers are required to scoop it up (the thicker the poi, the fewer fingers required to scoop a sufficient mouthful).
Poi can be eaten immediately, when fresh and sweet, or left a bit longer to ferment and become more sour – it then develops a smell reminiscent of plain yoghurt. A layer of water on top can prevent fermenting poi from developing a crust.Portulacineae
Portulacineae is a suborder of flowering plants in the order Caryophyllales comprising the families Anacampserotaceae, Basellaceae, Cactaceae (cacti), Didiereaceae, Halophytaceae, Montiaceae, Portulacaceae, and Talinaceae. All three major kinds of succulent plant — stem succulents, leaf succulents, and caudiciform plants — are represented within this suborder.Rhizome
In botany and dendrology, a rhizome (, from Ancient Greek: rhízōma "mass of roots", from rhizóō "cause to strike root") is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow horizontally. The rhizome also retains the ability to allow new shoots to grow upwards.A rhizome is the main stem of the plant. A stolon is similar to a rhizome, but a stolon sprouts from an existing stem, has long internodes, and generates new shoots at the end, such as in the strawberry plant. In general, rhizomes have short internodes, send out roots from the bottom of the nodes, and generate new upward-growing shoots from the top of the nodes.
A stem tuber is a thickened part of a rhizome or stolon that has been enlarged for use as a storage organ. In general, a tuber is high in starch, e.g. the potato, which is a modified stolon. The term "tuber" is often used imprecisely and is sometimes applied to plants with rhizomes.
If a rhizome is separated each piece may be able to give rise to a new plant. The plant uses the rhizome to store starches, proteins, and other nutrients. These nutrients become useful for the plant when new shoots must be formed or when the plant dies back for the winter. This is a process known as vegetative reproduction and is used by farmers and gardeners to propagate certain plants. This also allows for lateral spread of grasses like bamboo and bunch grasses. Examples of plants that are propagated this way include hops, asparagus, ginger, irises, lily of the valley, cannas, and sympodial orchids. Some rhizomes which are used directly in cooking include ginger, turmeric, galangal, fingerroot, and lotus.
Stored rhizomes are subject to bacterial and fungal infections, making them unsuitable for replanting and greatly diminishing stocks. However, rhizomes can also be produced artificially from tissue cultures. The ability to easily grow rhizomes from tissue cultures leads to better stocks for replanting and greater yields. The plant hormones ethylene and jasmonic acid have been found to help induce and regulate the growth of rhizomes, specifically in rhubarb. Ethylene that was applied externally was found to affect internal ethylene levels, allowing easy manipulations of ethylene concentrations. Knowledge of how to use these hormones to induce rhizome growth could help farmers and biologists producing plants grown from rhizomes more easily cultivate and grow better plants.
Some plants have rhizomes that grow above ground or that lie at the soil surface, including some Iris species, and ferns, whose spreading stems are rhizomes. Plants with underground rhizomes include gingers, bamboo, the Venus flytrap, Chinese lantern, western poison-oak, hops, and Alstroemeria, and the weeds Johnson grass, Bermuda grass, and purple nut sedge. Rhizomes generally form a single layer, but in giant horsetails, can be multi-tiered.Many rhizomes have culinary value, and some, such as zhe'ergen, are commonly consumed raw.Tasmanian darner
The Tasmanian darner, (Austroaeschna tasmanica), is a species of large dragonfly in the family Telephlebiidae, which includes some of the world's largest dragonflies. It is found in Tasmania, Australia. The species was first described by Robert Tillyard in 1916 and inhabits streams and rivers.Also referred to as "hawkers", the name "darner" derives from the fact that the female abdomen looks like a sewing needle, as it cuts into a plant stem when the female dragonfly lays her eggs through her ovipositor.
The Tasmanian darner is a stout, dark dragonfly with a very dark colouring and light markings. It appears similar to the lesser Tasmanian darner, Austroaeschna hardyi.Zha cai
Zha cai ([ʈʂâ tsʰâi]; 榨菜) is a type of pickled mustard plant stem originating from Chongqing, China. The name may also be written in English as cha tsai, tsa tsai, jar choy, jar choi, ja choi, ja choy, or cha tsoi. In English, it is commonly known as Sichuan vegetable, Szechwan vegetable, or Chinese pickled vegetable, although all of these terms may also refer to any of a number of other Chinese pickles, including the several other types in the Sichuan province itself.
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