Stem showing internode and nodes plus leaf petioles

A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence (flowers), conifer cones, roots, other stems etc. The internodes 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. The other main structural axis of plants is the root. In most plants stems are located above the soil surface but some plants have underground stems. A stem develops buds and shoots and usually grows above the ground. Inside the stem, materials move up and down the tissues of the transport system.

Stems have four main functions which are:^[1]

• Support for and the elevation of leaves, flowers and fruits. The stems keep the leaves in the light and provide a place for the plant to keep its flowers and fruits.
• Transport of fluids between the roots and the shoots in the xylem and phloem.
• Storage of nutrients.
• The production of new living tissue. The normal life span of plant cells is one to three years. Stems have cells called meristems that annually generate new living tissue.

Specialized terms for stems[link]

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

• Acaulescent - used to describe stems in plants that appear to be stemless. Actually these stems are just extremely short, the leaves appearing to rise directly out of the ground, e.g. some Viola species.
• Arborescent - tree like with woody stems normally with a single trunk.
• Bud - an embryonic shoot with immature stem tip.
• Bulb - a short vertical underground stem with fleshy storage leaves attached, e.g. onion, daffodil, tulip. Bulbs often function in reproduction by splitting to form new bulbs or producing small new bulbs termed bulblets. Bulbs are a combination of stem and leaves so may better be considered as leaves because the leaves make up the greater part.
• Caespitose - when stems grow in a tangled mass or clump or in low growing mats.
• Cladode (including phylloclade) - a flattened stem that appears more-or-less leaf like and is specialized for photosynthesis,^[2] e.g. cactus pads.
• Climbing - stems that cling or wrap around other plants or structures.
• Corm - a short enlarged underground, storage stem, e.g. taro, crocus, gladiolus.
• Decumbent - stems that lie flat on the ground and turn upwards at the ends.
• Fruticose - stems that grow shrublike with woody like habit.
• Herbaceous - non woody, they die at the end of the growing season.
• Prickle - a sharpened extension of the stem's outer layers, e.g. roses.
• Pseudostem - a false stem made of the rolled bases of leaves, which may be 2 or 3 m tall as in banana
• Rhizome - a horizontal underground stem that functions mainly in reproduction but also in storage, e.g. most ferns, iris
• Runner (plant part) - a type of stolon, horizontally growing on top of the ground and rooting at the nodes, aids in reproduction. e.g. garden strawberry, Chlorophytum comosum.
• Scape - a stem that holds flowers that comes out of the ground and has no normal leaves. Hosta, Lily, Iris, Garlic.
• Stolon - a horizontal stem that produces rooted plantlets at its nodes and ends, forming near the surface of the ground.
• Thorn - a modified stem with a sharpened point.
• Tree - a woody stem that is longer than 5 metres with a main trunk.
• Tuber - a swollen, underground storage stem adapted for storage and reproduction, e.g. potato.
• Woody - hard textured stems with secondary xylem.

Stem structure[link]

Flax stem cross-section, showing locations of underlying tissues. 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. 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[link]

Dicot stem 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. 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.

Monocot stems[link]

Stems of two Roystonea regia palms showing characteristic bulge, leaf scars and fibrous roots, Kolkata, India

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.

Gymnosperm stems[link]

The trunk of this redwood tree is its stem.

Tasmanian tree fern

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.

Fern stems[link]

Most ferns have rhizomes with no vertical stem. The exception is tree ferns, with vertical stems up to about 20 meters. 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. .

Relation to xenobiotics[link]

Foreign chemicals such as air pollutants,^[3] herbicides and pesticides can damage stem structures. In the case of herbicides many chemicals act by surficial effects, and other agents cause damage through uptake of the chemical herbicide, which is typically a complex organic chemical.

Economic importance[link]

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

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. Cellulose from tree trunks is a food additive in bread, grated Parmesan cheese, and other processed foods.^{[citation needed]} 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. Reed stems are also important building materials 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.:

• White bark of paper birch
• Twisted branches of corkscrew willow and Harry Lauder's walking stick (Corylus avellana 'Contorta')
• Red, peeling bark of paperbark maple

[edit] References

v t e Botany Subdisciplines of botany Ethnobotany Paleobotany Plant anatomy Plant ecology Plant evo-devo Plant morphology Plant physiology Plants Evolutionary history of plants Algae Bryophyte Pteridophyte Gymnosperm Angiosperm Plant parts Flower Fruit Leaf Meristem Root Stem Stoma Vascular tissue Wood Plant cells Cell wall Chlorophyll Chloroplast Photosynthesis Plant hormone Plastid Transpiration Plant reproduction Alternation of generations Gametophyte Plant sexuality Pollen Pollination Seed Spore Sporophyte Plant taxonomy Botanical name Botanical nomenclature Herbarium IAPT ICN Species Plantarum Glossaries Glossary of botanical terms Glossary of plant morphology terms Category Portal

Sam Lam (born November 24, 1987 in Edmonton, Alberta) is a Canadian soccer player.

Career[link]

Youth and college[link]

Lam played college soccer at the University of Alberta for the Golden Bears.^[1]

Professional[link]

After trialing with Seattle Sounders FC of Major League Soccer, Lam played professional indoor soccer for the Edmonton Drillers in the Canadian Major Indoor Soccer League in 2010, before being signed by FC Edmonton of the new North American Soccer League in 2011.^[2] He made his professional debut in in the team's first competitive game on April 9, 2011, a 2-1 victory over the Fort Lauderdale Strikers.^[3] The club released Lam on October 12, 2011 after the conclusion of the 2011 season.^[4]

References[link]

External links[link]

• FC Edmonton bio

Shahnaz Husain, CEO of Shahnaz Herbals Inc, is a prominent Indian female entrepreneur best known for her herbal cosmetics, particularly skin care products. In 2006 she was awarded the Padma Shri, a civilian award by the Government of India in 2006,^[1] and in 1996 Success Magazine's "World's Greatest Woman Entrepreneur" award.^[2]

She was educated at La Martiniere Lucknow.^[3]

The Shahnaz Husain Group has over 400 franchise clinics across the world covering over 138 countries.

References[link]

External links[link]

• Official Website
• Official Online Store
• Official Blog

• http://ibnlive.in.com/videos/247001/flame-shahnaz-husains-daughter-pens-biography.html

Jeff Turner

No. 35, 30, 31
Power forward
Personal information
Born	(1962-04-09) April 9, 1962 (age 50) Bangor, Maine
Nationality	American
High school	Brandon (Brandon, Florida)
Listed height	6 ft 9 in (2.06 m)
Listed weight	230 lb (104 kg)
Career information
College	Vanderbilt (1980–1984)
NBA Draft	1984 / Round: 1 / Pick: 17th overall
Selected by the New Jersey Nets
Pro career	1984–1996
Career history
1984–1987	New Jersey Nets
1986–1989	Arexons / Vismara Cantù (Italy)
1989–1996	Orlando Magic
Stats at Basketball-Reference.com
Medals Men's Basketball Competitor for  United States Gold 1984 Los Angeles National team World Championships Silver 1982 Colombia National team

Jeffrey Steven Turner (born April 9, 1962 in Bangor, Maine) is a retired American professional basketball player and broadcasting announcer. Turner played ten NBA seasons (1984–1987; 1989–1996), spending time with the New Jersey Nets as well as the Orlando Magic. He ended his NBA career with 3,697 career points. Turner was a 6' 9" forward/center. After his career ended he spent nine years as a color commentator for the Magic. He currently serves as the head boys basketball coach at Lake Highland Preparatory School in Orlando, Florida

Turner starred as a college player for Vanderbilt University. He was selected by the New Jersey Nets with the 17th pick of the 1984 NBA Draft.

Turner was a member of the Gold Medal 1984 U.S. Olympic basketball team coached by Bobby Knight. The team included Michael Jordan, Patrick Ewing and Steve Alford. Turner also played for the US national team in the 1982 FIBA World Championship, winning the silver medal.^[1]

Controversy[link]

On June 4, 2008, the Associated Press reported that Ronnie Craven of Somerville, Massachusetts, had been posing as Turner and using the identity to facilitate sexual encounters with women he met in online chat rooms. His ruse also included the additional falsehood that "Jeff Turner" was employed in the front office of the Seattle SuperSonics (Turner has never worked for the Sonics). Craven says he has received a cease-and-desist order from a lawyer for the Sonics. Craven said he was embarrassed and would stop lying about his identity.^[2]

See also[link]

• Vanderbilt Commodores men's basketball

References[link]

External links[link]

• Jeff Turner at Basketball-Reference.com

v t e 1984 Olympic Champions Men's Basketball team - United States 4 Alford 5 Turner 6 Ewing 7 Fleming 8 Robertson 9 Jordan 10 Kleine 11 Koncak 12 Mullin 13 Tisdale 14 Perkins 15 Wood Coach: Knight

This biographical article relating to a United States basketball player, coach, or other figure born in the 1960s is a stub. You can help Wikipedia by expanding it. v t e