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A stem is one of two main structural axes of a
vascular plant Vascular plants (from Latin ''vasculum'': duct), also known as Tracheophyta (the tracheophytes , from Greek τραχεῖα ἀρτηρία ''trācheia artēria'' 'windpipe' + φυτά ''phutá'' 'plants'), form a large group of plants ( 300,000 ...
, the other being the
root In vascular plant Vascular plants (from Latin ''vasculum'': duct), also known as Tracheophyta (the tracheophytes , from Greek τραχεῖα ἀρτηρία ''trācheia artēria'' 'windpipe' + φυτά ''phutá'' 'plants'), form a large group ...

root
. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, stores nutrients, and produces new living tissue. The stem is normally divided into nodes and internodes: * The nodes hold one or more leaves, as well as
bud In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the An ...

bud
s which can grow into branches (with
leaves A leaf (plural leaves) is the principal lateral appendage of the vascular plant plant stem, stem, usually borne above ground and specialized for photosynthesis. The leaves, stem, flower and fruit together form the shoot system. Leaves are ...

leaves
,
conifer cone (''Pinus coulteri'') cone, the heaviest pine cone A conifer cone (in formal botany, botanical usage: strobilus A strobilus (plural: strobili) is a structure present on many land plant Plants are mainly multicellular organisms, predomi ...
s, or
inflorescence An inflorescence is a group or cluster of s arranged on a that is composed of a main or a complicated arrangement of branches. , it is the modified part of the of where s are formed. The modifications can involve the length and the nature ...
s (flowers)).
Adventitious rootsImportant structures in plant development are buds, shoots, root In vascular plants, the roots are the plant organ, organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which ...

Adventitious roots
may also be produced from the nodes. * The internodes distance one node from another. The term "
shoot In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancie ...

shoot
s" 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 stemsUnderground stems are modified plants that derive from stem Stem or STEM may refer to: Biology * Plant stem '' has lost its leaves, but is producing adventitious roots from the nodes. A stem is one of two main structural axes of a vascular pla ...
. Stems have four main functions which are: * Support for and the elevation of leaves,
flower A flower, sometimes known as a bloom or blossom Cherry blossoms in Paris in full bloom. In botany, blossoms are the flowers of stone fruit fruit tree, trees (genus ''Prunus'') and of some other plants with a similar appearance that flower prof ...

flower
s and
fruit In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the ...

fruit
s. 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 Xylem is one of the two types of transport in s, the other being . The basic function of xylem is to transport from roots to stems and leaves, but it also transports . The word ''xylem'' is derived from the word (''xylon''), meaning "wood"; ...

xylem
and
phloem Phloem (, ) is the living tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a species of geometer moth found in North America * ''Triphosa d ...

phloem
(see below) * Storage of nutrients * Production of new living tissue. The normal lifespan of plant cells is one to three years. Stems have cells called
meristem The meristem is a type of tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a species of geometer moth found in North America * ''Triphosa du ...
s that annually generate new living tissue. Stems have two pipe-like tissues called
xylem Xylem is one of the two types of transport in s, the other being . The basic function of xylem is to transport from roots to stems and leaves, but it also transports . The word ''xylem'' is derived from the word (''xylon''), meaning "wood"; ...

xylem
and
phloem Phloem (, ) is the living tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a species of geometer moth found in North America * ''Triphosa d ...

phloem
. The xylem tissue transports water by the action of
transpiration pull Xylem is one of the two types of transport tissue in vascular plant Vascular plants (from Latin ''vasculum'': duct), also known as Tracheophyta (the tracheophytes , from the Greek ''trācheia''), form a large group of plants ( 300,000 accepte ...
,
capillary action Capillary action (sometimes capillarity, capillary motion, capillary effect, or wicking) is the ability of a liquid A liquid is a nearly incompressible In fluid mechanics or more generally continuum mechanics, incompressible flow (isocho ...
and
root pressure' Primary and secondary roots in a cotton plant Root pressure is the transverse osmotic pressure within the cells of a root system that causes sap to rise through a plant stem to the leaves. Root pressure occurs in the xylem of some vascular plant ...
. The phloem tissue consists of sieve tubes and their companion cells. The two tissues are separated by
cambium A cambium (plural cambia or cambiums), in plants, is a tissue layer that provides partially undifferentiated cell Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Closed spaces * Monastic ...
which is a tissue that divides to form xylem or phloem cells.


Specialized terms

Stems are often specialized for storage, asexual reproduction, protection or photosynthesis, including the following: *
Acaulescent This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary of le ...

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 with woody stems normally with a single trunk. *
Axillary bud The axillary bud (or lateral bud) is an Plant embryogenesis, embryonic or Organogenesis#Plant organogenesis, organogenic shoot located in the axil of a leaf. Each bud has the potential to form shoots, and may be specialized in producing either vege ...
: a bud which grows at the point of attachment of an older leaf with the stem. It potentially gives rise to a shoot. *
Branch A branch ( or , ) or tree branch (sometimes referred to in botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who spe ...

Branch
ed: aerial stems are described as being branched or unbranched. *
Bud In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the An ...

Bud
: an embryonic shoot with immature stem tip. *
Bulb In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the An ...

Bulb
: a short vertical underground stem with fleshy storage leaves attached, e.g.
onion The onion (''Allium cepa'' L., from Latin ''cepa'' "onion"), also known as the bulb onion or common onion, is a vegetable Vegetables are parts of plants that are consumed by humans or other animals as food. The original meaning is still com ...

onion
,
daffodil ''Narcissus'' is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology Biology is the natural science that studies life and living organisms, including ...

daffodil
,
tulip Tulips (''Tulipa'') are a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology Biology is the natural science that studies life and living organisms, inclu ...

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 Phylloclades and cladodes are flattened, photosynthetic Photosynthesis is a process used by plants and other organisms to Energy transformation, convert light energy into chemical energy that, through cellular respiration, can later be releas ...
): a flattened stem that appears more-or-less leaf like and is specialized for photosynthesis, e.g.
cactus A cactus (plural cacti, cactuses, or less commonly, cactus) is a member of the plant Plants are predominantly photosynthetic Photosynthesis is a process used by plants and other organisms to Energy transformation, convert light en ...

cactus
pads. *
Climbing Climbing is the activity of using one's hands, feet, or any other part of the body to ascend a steep topographical object. It is done for locomotion, recreation and competition, and within trades that rely on ascension; such as emergency re ...

Climbing
: stems that cling or wrap around other plants or structures. *
Corm A corm, bulbo-tuber, or bulbotuber is a short, vertical, swollen underground plant stem '' has lost its leaves, but is producing adventitious rootsImportant structures in plant development are buds, shoots, root In vascular plants, the ro ...

Corm
: a short enlarged underground, storage stem, e.g.
taro ''Colocasia esculenta'' is a tropical plant grown primarily for its edible corm A corm, bulbo-tuber, or bulbotuber is a short, vertical, swollen underground plant stem '' has lost its leaves, but is producing adventitious rootsImportant ...

taro
,
crocus ''Crocus'' (English plural: crocuses or croci) is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology Biology is the natural science that studies life an ...

crocus
,
gladiolus ''Gladiolus'' (from Latin, the diminutive of '' gladius'', a sword) is a genus of perennial cormous flowering plants in the iris family (Iridaceae). It is sometimes called the 'sword lily', but is usually called by its generic name (plural ...

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 Herbaceous plants are vascular plants that have no persistent wood, woody stems above ground, including many perennial plant, perennials, and nearly all Annual plant, annuals and Biennial plant, biennials. Definitions of "herb" and "herbaceous" ...
: non woody, they die at the end of the growing season. * Internode: an interval between two successive nodes. It possesses the ability to elongate, either from its base or from its extremity depending on the species. * Node: a point of attachment of a leaf or a
twig A twig or stick is a thin branch A branch ( or , ) or tree branch (sometimes referred to in botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientis ...

twig
on the stem in seed plants. A node is a very small growth zone. *
Pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures * ...
: stems that serve as the stalk of an individual flower in an
inflorescence An inflorescence is a group or cluster of s arranged on a that is composed of a main or a complicated arrangement of branches. , it is the modified part of the of where s are formed. The modifications can involve the length and the nature ...
or infrutescence. * Peduncle: a stem that supports an
inflorescence An inflorescence is a group or cluster of s arranged on a that is composed of a main or a complicated arrangement of branches. , it is the modified part of the of where s are formed. The modifications can involve the length and the nature ...
. * Prickle: a sharpened extension of the stem's outer layers, e.g.
rose A rose is a woody perennial plant, perennial flowering plant of the genus ''Rosa'', in the family Rosaceae, or the flower it bears. There are over three hundred Rose species, species and Garden roses, tens of thousands of cultivars. They form ...

rose
s. * Pseudostem: a false stem made of the rolled bases of leaves, which may be tall, as in
banana A banana is an elongated, edible fruit In botany, a fruit is the seed-bearing structure in flowering plants (also known as angiosperms) formed from the ovary after flowering. Fruits are the means by which angiosperms dissemin ...

banana
. *
Rhizome In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the A ...

Rhizome
: a horizontal underground stem that functions mainly in reproduction but also in storage, e.g. most
fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plant Vascular plants (from Latin ''vasculum'': duct), also known as Tracheophyta (the tracheophytes , from Greek τραχεῖα ἀρτηρία ''trācheia art ...

fern
s,
iris
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 The garden strawberry (or simply strawberry; ''Fragaria × ananassa'') is a widely grown hybrid species of the genus '' Fragaria'', collectively known as the strawberries, which are cultivated worldwide for their fruit In botany, a frui ...
, ''
Chlorophytum comosum ''Chlorophytum comosum'', usually called spider plant but also known as spider ivy, ribbon plant, and hen and chickens is a species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of ...

Chlorophytum comosum
''. * Scape: a stem that holds flowers that comes out of the ground and has no normal leaves.
Hosta ''Hosta'' (, syn. ''Funkia'') is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription ...

Hosta
,
lily ''Lilium'' is a genus of Herbaceous plant, herbaceous flowering plants growing from bulbs, all with large prominent flowers. They are the true lilies. Lilies are a group of flowering plants which are important in culture and literature in much ...

lily
,
iris
iris
,
garlic Garlic (''Allium sativum'') is a species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest ...

garlic
. *
Stolon In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular interactions, Physiology, physiological mechanisms ...
: a horizontal stem that produces rooted plantlets at its nodes and ends, forming near the surface of the ground. *
Thorn Thorne or Thorns may refer to: Botany * Thorns, spines, and prickles, sharp structures on plants * Thorn, quickthorn or common hawthorn (''Crataegus monogyna'') Places * Thorn, Netherlands * Thorn, German name of Toruń, Poland * Thorn, Bedfor ...
: a modified stem with a sharpened point. *
Tuber Tubers are enlarged structures used as storage organs for nutrients in some plants. They are used for the plant's perennation (survival of the winter or dry months), to provide energy and nutrients for regrowth during the next growing season, and ...
: a swollen, underground storage stem adapted for storage and reproduction, e.g.
potato The potato is a starch#Food, starchy tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial plant, perennial in the nightshade family Solanaceae. Wild potato species can be found thro ...

potato
. * Woody: hard textured stems with secondary xylem.


Stem structure

Stem usually consist of three tissues, dermal tissue,
ground tissue The ground tissue of plants includes all tissues that are neither dermal The dermis or corium is a layer of skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: prot ...
and
vascular tissue Vascular tissue is a complex conducting tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a species of geometer moth found in North Ameri ...
. 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 The dicotyledons, also known as dicots (or more rarely dicotyls), are one of the two groups into which all the flowering plant Flowering plants include multiple members of the clade Angiospermae (), commonly called angiosperms. The term "a ...
stems with primary growth have
pith Pith, or medulla, is a tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a species of geometer moth found in North America * ''Triphosa d ...
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 File:LeafUndersideWithStomata.jpg, The underside of a leaf. In this species (''Tradescantia zebrina'') the guard cells of the stomata are green because they contain chlorophyll while the epidermal cells are chlorophyll-free and contain red pigme ...

stomata
for gas exchange and multicellular stem hairs called
trichomes Flower bud of a '' Capsicum pubescens'' plant, with many trichomes Trichomes ( or ), from the Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic ...

trichomes
. A cortex consisting of
hypodermis The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, superficial fascia, is the lowermost layer of the integumentary system in vertebrates. The types of cells found in the layer are fibroblasts, adipose cells, and macrop ...
(collenchyma cells) and
endodermis The endodermis is the central, innermost layer of cortex in land plants The Embryophyta () or land plants are the most familiar group of green plants that form vegetation on earth. Embryophyta is a clade A clade (; from grc, , ''klados'' ...
(starch containing cells) is present above the
pericycle The pericycle is a cylinder of parenchyma or sclerenchyma cells that lies just inside the endodermis and is the outer most part of the stele of plants. Although it is composed of non-vascular parenchyma cells, it's still considered part of the ...
and vascular bundles. Woody dicots and many nonwoody dicots have
secondary growth In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Anc ...
originating from their lateral or secondary meristems: the
vascular cambium The vascular cambium is the main growth tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a species of geometer moth found in North America * ...
and the
cork cambium Cork cambium (pl. cambia or cambiums) is a tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a species of geometer moth found in North Americ ...
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 Bark is the outermost layers of stems and root In vascular plant Vascular plants (from Latin ''vasculum'': duct), also known as Tracheophyta (the tracheophytes , from Greek τραχεῖα ἀρτηρία ''trācheia artēria'' 'windpipe' + ...
, which replaces the epidermis in function. Areas of loosely packed cells in the periderm that function in gas exchange are called lenticels. Secondary
xylem Xylem is one of the two types of transport in s, the other being . The basic function of xylem is to transport from roots to stems and leaves, but it also transports . The word ''xylem'' is derived from the word (''xylon''), meaning "wood"; ...

xylem
is commercially important as
wood Wood is a porous and fibrous structural tissue found in the stems and roots of tree In botany, a tree is a perennial plant with an elongated Plant stem, stem, or trunk (botany), trunk, supporting branches and leaves in most species. ...

wood
. The seasonal variation in growth from the
vascular cambium The vascular cambium is the main growth tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a species of geometer moth found in North America * ...
is what creates yearly tree rings in temperate climates. Tree rings are the basis of
dendrochronology Dendrochronology (or tree-ring dating) is the scientific method The scientific method is an Empirical evidence, empirical method of acquiring knowledge that has characterized the development of science since at least the 17th century. It in ...
, which dates wooden objects and associated artifacts.
Dendroclimatology Dendroclimatology is the science of determining past climates from trees (primarily properties of the annual tree rings). Tree rings are wider when conditions favor growth, narrower when times are difficult. Other properties of the annual rings, ...
is the use of tree rings as a record of past climates. The aerial stem of an adult
tree In botany, a tree is a perennial plant with an elongated Plant stem, stem, or trunk (botany), trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only wood plants with se ...

tree
is called a trunk. The dead, usually darker inner wood of a large diameter trunk is termed the
heartwood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plant A woody plant is a plant Plants are mainly multicellular organisms, predominantly photosynthetic Photosynthesis is a p ...

heartwood
and is the result of tylosis. The outer, living wood is termed the sapwood.


Monocot stems

Vascular bundles are present throughout the
monocot Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one Embryo#Plant embryos, embryonic leaf, or cotyledon. The ...
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 In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Anc ...
and are therefore seldom woody, with
Palms
Palms
and
Bamboo Bamboos are a diverse group of evergreen In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in th ...

Bamboo
being notable exceptions. However, many monocot stems increase in diameter via anomalous secondary growth.


Gymnosperm stems

All
gymnosperms The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also ...
are woody plants. Their stems are similar in structure to woody dicots except that most gymnosperms produce only
tracheid A tracheid is a long and tapered lignified cell in the xylem Xylem is one of the two types of transport in s, the other being . The basic function of xylem is to transport from roots to stems and leaves, but it also transports . The word ' ...
s in their xylem, not the vessels found in dicots. Gymnosperm wood also often contains
resin In polymer chemistry Polymer chemistry is a sub-discipline of chemistry Chemistry is the study of the properties and behavior of . It is a that covers the that make up matter to the composed of s, s and s: their composition, stru ...

resin
ducts. Woody dicots are called hardwoods, e.g.
oak An oak is a tree In botany, a tree is a perennial plant with an elongated Plant stem, stem, or trunk (botany), trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including on ...

oak
,
maple ''Acer'' is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (taxonomy), circumscr ...

maple
and
walnut A walnut is the Nut (fruit), nut of any tree of the genus ''Juglans'' (family Juglandaceae), particularly the Persian or English walnut, ''Juglans regia''. A walnut is the edible seed of a drupe, and thus not a true botanical nut. It is com ...

walnut
. In contrast, softwoods are gymnosperms, such as
pine A pine is any conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The div ...

pine
,
spruce A spruce is a tree In botany, a tree is a perennial plant with an elongated Plant stem, stem, or trunk (botany), trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including ...

spruce
and
fir Firs (''Abies'') are a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology Biology is the natural science that studies life and living organisms, including ...

fir
. Image:Redwood M D Vaden.jpg, The trunk of this
redwood Sequoioideae, popularly known as redwoods, is a subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family (biology), family but more inclusive than genus. Standa ...

redwood
tree is its stem. Image:Ferns.jpg,
Tasmanian Tasmania (), abbreviated as TAS, is an island An island (or isle) is an isolated piece of habitat that is surrounded by a dramatically different habitat, such as water. Very small islands such as emergent land features on atol ...

Tasmanian
tree fern The tree ferns are the fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seed A seed is an embryonic plant enclosed i ...

tree fern


Fern stems

Most
fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plant Vascular plants (from Latin ''vasculum'': duct), also known as Tracheophyta (the tracheophytes , from Greek τραχεῖα ἀρτηρία ''trācheia art ...

fern
s have
rhizome In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the A ...

rhizome
s 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 Image:Fern frond lobed.jpg, 300px, A fern (''Dryopteris decipiens'') with simple (lobed or pinnatifid) blades, the dissection of each blade not quite reaching to the rachis. A frond is a large, divided leaf. In both common usage and botanical no ...

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

Foreign chemicals such as air pollutants,C. Michael Hogan. 2010
"Abiotic factor"
''Encyclopedia of Earth''. Emily Monosson and C. Cleveland, eds. National Council for Science and the Environment . Washington, D.C.
herbicides and pesticides can damage stem structures.


Economic importance

There are thousands of species whose stems have economic uses. Stems provide a few major staple crops such as
potato The potato is a starch#Food, starchy tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial plant, perennial in the nightshade family Solanaceae. Wild potato species can be found thro ...

potato
and
taro ''Colocasia esculenta'' is a tropical plant grown primarily for its edible corm A corm, bulbo-tuber, or bulbotuber is a short, vertical, swollen underground plant stem '' has lost its leaves, but is producing adventitious rootsImportant ...

taro
.
Sugarcane Sugarcane or sugar cane is a species of (often hybrid) tall, perennial A perennial plant or simply perennial is a plant Plants are predominantly photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, ...

Sugarcane
stems are a major source of sugar.
Maple sugar Maple sugar is a traditional sweetener in Canada and the northeastern United States, prepared from the sap of the maple tree ("maple sap"). Sources Three species of maple trees in the genus '' Acer'' are predominantly used to produce maple s ...
is obtained from trunks of
maple ''Acer'' is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (taxonomy), circumscr ...

maple
trees.
Vegetable Vegetables are parts of plants that are consumed by humans or other animals as food. The original meaning is still commonly used and is applied to plants collectively to refer to all edible plant matter, including the flowers A flower, som ...

Vegetable
s from stems are
asparagus Asparagus, or garden asparagus, folk name sparrow grass, scientific name ''Asparagus officinalis'', is a perennial A perennial plant or simply perennial is a plant Plants are predominantly photosynthetic eukaryotes of the Kingdom ...

asparagus
,
bamboo shoot Bamboo shoots or bamboo sprouts are the edible shoot In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specia ...

bamboo shoot
s, cactus pads or
nopalito Nopalitos is a Mexican cuisine, dish made with diced nopales, the naturally flat stems, called pads, of prickly pear cactus (''Opuntia''). They are sold fresh, bottled, or canning, canned and less often drying (food), dried. They have a light, sl ...

nopalito
s,
kohlrabi Kohlrabi (pronounced ; scientific name ''Brassica oleracea ''Brassica oleracea'' is a plant species that includes many common foods as cultivars, including cabbage, broccoli, cauliflower, kale, Brussels sprouts, collard greens, Savoy cabbage ...

kohlrabi
, and
water chestnutWater chestnut may refer to either of two plants (both sometimes used in Chinese cuisine): * The Chinese water chestnut ('' Eleocharis dulcis''), eaten for its crisp corm * The water caltrop (''Trapa natans''), eaten for its starchy seed See also ...

water chestnut
. The spice,
cinnamon Cinnamon is a spice A spice is a seed A seed is an embryonic ''Embryonic'' is the twelfth studio album by experimental rock band the Flaming Lips released on October 13, 2009, on Warner Bros. Records, Warner Bros. The band's first do ...

cinnamon
is bark from a tree trunk.
Gum arabic '', pictured in a medicinal handbook: Franz Eugen Köhler, ''Köhler's Medizinal-Pflanzen'' (1887) Gum arabic, also known as ''gum sudani'', acacia gum, Arabic gum, gum acacia, acacia, Senegal gum, ''Indian gum'', and by other names, is a natur ...
is an important food additive obtained from the trunks of ''
Acacia senegal ''Senegalia senegal'' (also known as ''Acacia senegal'') is a small thorny deciduous tree from the genus '' Senegalia'', which is known by several common names, including gum acacia, gum arabic tree, Sudan gum and Sudan gum arabic. In parts of In ...
'' trees.
Chicle Chicle () is a natural gum Natural gums are polysaccharides of natural origin, capable of causing a large increase in a solution's viscosity, even at small concentrations. They are mostly gum (botany), botanical gums, found in the woody element ...
, the main ingredient in
chewing gum Chewing gum is a soft, cohesive substance designed to be chewed without being swallowed. Modern chewing gum is composed of gum baseGum base is the non-nutritive, non-digestible, water-insoluble Mastication, masticatory delivery system used to ...
, is obtained from trunks of the chicle tree. Medicines obtained from stems include
quinine Quinine is a medication used to treat malaria Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms Signs and symptoms are the observed or detectable signs, and experienced sympto ...

quinine
from the bark of
cinchona ''Cinchona'' (pronounced or ) is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV class ...
trees,
camphor Camphor () is a wax Waxes are a diverse class of organic compound In , organic compounds are generally any s that contain - . Due to carbon's ability to (form chains with other carbon s), millions of organic compounds are known. The ...

camphor
distilled from wood of a tree in the same genus that provides cinnamon, and the muscle relaxant
curare Curare ( /kʊˈrɑːri/ or /kjʊˈrɑːri/; ''koo-rah-ree'' or ''kyoo-rah-ree'') is a common name for various plant extract alkaloid Alkaloids are a class of base (chemistry), basic, natural product, naturally occurring organic compoun ...

curare
from the bark of tropical vines.
Wood Wood is a porous and fibrous structural tissue found in the stems and roots of tree In botany, a tree is a perennial plant with an elongated Plant stem, stem, or trunk (botany), trunk, supporting branches and leaves in most species. ...

Wood
is used in thousands of ways, e.g.
buildings A building, or edifice, is a structure A structure is an arrangement and organization of interrelated elements in a material object or system A system is a group of Interaction, interacting or interrelated elements that act according to a se ...

buildings
,
furniture Furniture refers to movable objects intended to support various human activities such as seating (e.g., chairs, stools, and sofas), eating (table (furniture), tables), and sleeping (e.g., beds). Furniture is also used to hold objects at a con ...

furniture
,
boat A boat is a watercraft Watercraft, also known as water vessels or waterborne vessels, are vehicles A vehicle (from la, vehiculum) is a machine A machine is any physical system with ordered structural and functional properties. It m ...

boat
s,
airplane An airplane or aeroplane (informally plane) is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, Propeller (aircraft), propeller, or rocket engine. Airplanes come in a variety of sizes, shapes, and wing configurati ...

airplane
s,
wagon A wagon or waggon is a heavy four-wheeled pulled by s or on occasion by humans, used for ing , commodities, agricultural materials, supplies and sometimes people. Wagons are immediately distinguished from s (which have two wheels) and from l ...

wagon
s,
car A car (or automobile) is a wheeled motor vehicle Electric bicycles parked in Yangzhou's main street, Wenchang Lu. They are a very common way of transport in this city, in some areas almost outnumbering regular bicycles A motor vehicle, also k ...

car
parts,
musical instrument A musical instrument is a device created or adapted to make musical sounds. In principle, any object that produces sound can be considered a musical instrument—it is through purpose that the object becomes a musical instrument. A person who play ...
s,
sports equipment Sporting equipment, also called sporting goods, are the tools, materials, apparel, and gear used to compete in a sport and varies depending on the sport. The equipment ranges from balls, nets, and protective gear Personal protective equipm ...
,
railroad tie A railroad tie, crosstie (American English American English (AmE, AE, AmEng, USEng, en-US), sometimes called United States English or U.S. English, is the set of variety (linguistics), varieties of the English language native to the Un ...
s, utility poles, fence posts, Deep foundation, pilings, toothpicks, matches, plywood, coffins, Shake (shingle), shingles, barrel staves, toys, tool handles, picture frames, wood veneer, 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 Bamboos are a diverse group of evergreen In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in th ...

Bamboo
stems also have hundreds of uses, including paper, buildings, furniture, boats, musical instruments, fishing poles, water pipes, plant stakes, and bamboo scaffolding, scaffolding. Trunks of palm trees and
tree fern The tree ferns are the fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seed A seed is an embryonic plant enclosed i ...

tree fern
s are often used for building. Stems of Phragmites, 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 tree, quebracho. Cork (material), 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, corkscrew willow and hazel, Harry Lauder's walking stick (''Corylus avellana'' 'Contorta') * Red, peeling bark of paperbark maple


References


Further reading

*


External links

* {{Authority control Plant anatomy, Stem Plant morphology, Stem