In
biologyBiology is the natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy...
,
stolons are horizontal connections between organisms. They may be part of the organism, or of its
skeletonIn biology, a skeleton is a rigid framework that provides protection and structure in many types of animal, particularly those of the phylum Chordata and of the superphylum Ecdysozoa. Exoskeletons are external, as is typical of many invertebrates; they enclose the soft tissues and organs of the...
; typically,
animalAnimals are a major group of mostly multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously...
stolons are external skeletons.
In botany
In
botanyBotany, plant science, phytology, or plant biology is a branch of biology and is the scientific study of plant life and development...
,
stemA 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 , cones or other stems etc. The internodes act as spaces that distance one node from another...
s which grow at the
soilSoil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics. It is composed of particles of broken rock that have been altered by chemical and...
surface or below ground form new plants at the ends or at the nodes. Stolons are often called
runners. Imprecisely they are stems that run atop or just under the ground; more specifically, a stolon is a horizontal shoot from a
plantPlants are living organisms belonging to the kingdom Plantae. They include familiar organisms such as trees, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The scientific study of plants, known as botany, has identified about 350,000 extant species of plants, defined as seed plants,...
that grows on top of or below the soil surface with the ability to produce new
clonesCloning in biology is the process of producing populations of genetically-identical individuals that occurs in nature when organisms such as bacteria, insects or plants reproduce asexually. Cloning in biotechnology refers to processes used to create copies of DNA fragments , cells , or organisms...
of the same plant from buds at the tip.
Stolons are stems
Stolons are similar to normal stems except they produce adventitious roots at the nodes and run horizontally rather than vertically. They also have long internodes with reduced leaves, with the exception of stolons in aqueous plants. Plants with stolons or stolon-like
rhizomeIn botany, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
s are called stoloniferous. A stolon is a
plant propagationPlant propagation is the process of artificially or naturally distributing plants.-Sexual propagation :Seeds and spores can be used for reproduction . Seeds are typically produced from sexual reproduction within a species, since because genetic recombination has occurred plants grown from seed may...
strategy and the complex of individuals formed by a mother plant and all its
clonesCloning in biology is the process of producing populations of genetically-identical individuals that occurs in nature when organisms such as bacteria, insects or plants reproduce asexually. Cloning in biotechnology refers to processes used to create copies of DNA fragments , cells , or organisms...
produced from stolons form a single genetic individual. Runners are a type of stolon that exist above ground and are produced by many plants, such as
strawberriesFragaria is a genus of flowering plants in the rose family, Rosaceae, commonly known as strawberries for their edible fruits. There are more than 20 described species and many hybrids and cultivars. The most common strawberries grown commercially are cultivars of the Garden strawberry...
. Stolons lack the same type of reduced leaves that rhizomes have at the nodes; stolons have scale-like leaves and new roots are formed at the nodes only while rhizomes typically have paper like leaves at the nodes. Typically, stolons have very long internodes that form new plants at the ends. These rise to the soil surface and can produce foliage and flowers. In contrast, rhizomes most often have short internodes with leaf-scars and thin paper-like leaves and root along the under side of the stem. Root formation does not correspond strictly to the nodes but roots can generate from areas around the scar-like nodes as well.
Morphology
Stolons are like long branches of a tree that grow horizontal to the soil surface and produce new plants at the ends, they have nodes and internodes, leaves that are reduced to scales and buds that grow into roots and shoots. Stolons arise from the base of the plant. In strawberries the base is above the soil surface; in many bulb-forming species and plants with rhizomes, the stolons remain underground and form shoots that rise to the surface at the ends or from the nodes. The nodes of the stolons produce roots, often all around the node and hormones produced by the roots cause the stolon to initiate shoots with normal leaves. Typically after the formation of the new plant the stolon dies away in a year or two, while rhizomes persist normally for many years or for the life of the plant, adding more length each year to the ends with active growth. Rhizomes are used as storage structures for nutrients and most often are covered with thin papery leaves (normally a translucent brownish color), while stolons are not covered with reduced leaves but have scales like leaves at the nodes that are most often white in color. Stolons look and act like
etiolatedEtiolation occurs when plants are grown in either partial or complete absence of light, and is characterized by long, weak stems; smaller, sparser leaves due to longer internodes; and a pale yellow color . This is a mechanism to increase the likeliness that a plant will reach a light source, often...
stems except for their orientation of growth, instead of stretching upward for light they grow laterally or downward. The horizontal growth of stolons results from the interplay of different hormones produced at the growing point and hormones from the main plant, with some studies showing that stolon and rhizome growth effected by the amount of shady light the plant receives with increased production and branching from plants exposed to mixed shade and sun, while plants in all day sun or all shade producing fewer stolons.
Often the general meaning of stolon (horizontal stems above ground) does not distinguish morphologically the differences between stolons and rhizomes but just differentiates rhizome and stolon from each other strictly by where they are found, with rhizomes being below ground. Though this generalization is imprecise with a number of plants having soil level or above ground rhizomes including
IrisIris is a genus of between 200–300 species of flowering plants with showy flowers. It takes its name from the Greek word for a rainbow, referring to the wide variety of flower colors found among the many species...
species and many orchid species. Because of this some botany texts now use the term underground stolon to refer to stolons that move under ground.
T. Holm (1929) restricted the term rhizome to a horizontal, usually subterranean, stem that produces roots from its lower surface and green leaves from its apex, developed directly from the plumule of the embryo. He recognized stolons as axillary, subterranean branches that do not bear green leaves but only membranaceous, scale-like ones.
Plants with stolons
In some
CyperusCyperus is a large genus of about 600 species of sedges, distributed throughout all continents in both tropical and temperate regions. They are annual or perennial plants, mostly aquatic and growing in still or slow-moving water up to 0.5 m deep. The species vary greatly in size, with small species...
species the stolons end with the growth of tubers; the tubers are swollen stolons that form new plants.
Some
speciesIn biology, a species is:* a taxonomic rank or* a unit at that rank ....
of crawling plants can also sprout adventitious roots, but are not considered stoloniferous: a stolon is sprouted from an existing stem and can produce a full individual. Examples of plants that extend through stolons include some species from the
generaIn biology, a genus is a taxonomic unit used in the classification of living and fossil organisms. The term comes from Latin genus "descent, family, type, gender" , cognate with – genos, "race, stock, kin" ..In addition, genus is a taxonomic rank in the hierarchy In biology, a genus (plural:...
ArgentinaArgentina is a genus of plants in the rose family . The circumscription is not yet fully settled; it includes at least three species long classified in Potentilla sect. Leptostylae. A further 23-25 or more species also traditionally included in Potentilla sect...
(silverweed),
CynodonNot to be confused with the vertebrate clade "Cynodont"Cynodon is a genus of nine species of grasses, native to warm temperate to tropical regions of the Old World. The genus as a whole as well as its species are commonly known as Bermuda Grass or Dog's Tooth Grass...
,
FragariaFragaria is a genus of flowering plants in the rose family, Rosaceae, commonly known as strawberries for their edible fruits. There are more than 20 described species and many hybrids and cultivars. The most common strawberries grown commercially are cultivars of the Garden strawberry...
, and
Pilosella (Hawkweeds),
ZoysiaZoysia is a genus of eight species of creeping grasses native to southeastern and eastern Asia and Australasia. These species, commonly called zoysia or zoysiagrass, are found in coastal areas or grasslands...
japonica,
Ranunculus repens.
Other plants with stolons below the soil surface include many grasses,
Ajuga,
MenthaMentha is a genus of about 25 species of flowering plants in the family Lamiaceae . Species within Mentha have a subcosmopolitan distribution across Europe, Africa, Asia, Australia, and North America. Several mint hybrids commonly occur.Mints are aromatic, almost exclusively perennial, rarely...
, and
StachysStachys is a genus of about 300 species of annual and perennial herbaceous plants and shrubs in the family Lamiaceae. The distribution of the genus covers Europe, Asia, Africa, Australasia and North America. Common names include heal-all, self-heal, woundwort, betony, lamb's ears, and hedgenettle...
.
Lily-of-the-valley (
Convallaria majalis) which has rhizomes that grow stolon-like stems called stoloniferous rhizomes or leptomorph rhizomes. A number of plants have stoloniferous rhizomes including
AsterAster can refer to one of the following:*Aster , a genus of flowering plants in the family Asteraceae*Callistephus, another genus of flowering plants in the family Asteraceae, commonly called Aster or Chinese Aster...
s These stolon-like rhizomes are long and thin, with long internodes and indeterminate growth with lateral buds at the node that mostly remain dormant.
In potatoes, the stolons start to grow within 10 days of plants emerging above ground, with tubers usually beginning to form on the end of the stolons. The tubers are modified stolons that hold food reserves with a few buds that grow into stems. Since it is
not a rhizome it does not generate roots, but the new stem growth that grows to the surface produces roots. See also
BBCH-scale (potato)The BBCH-scale identifies the phenological development stages of a potato . It is a plant species-specific version of the BBCH-scale.1 For second generation sprouts
...
HydrillaHydrilla is an aquatic plant genus, usually treated as containing just one species, Hydrilla verticillata, though some botanists divide it into several species. Synonyms include H. asiatica, H. japonica, H. lithuanica, and H. ovalifolica...
use stolons that produce tubers to spread themselves and survive dry periods in aquatic habitats.
ErythroniumErythronium is a genus of bulbous spring-flowering perennials. They have attractive pendant flowers and sometimes mottled leaves. They prefer shade....
commonly called Trout Lily, have white stolons growing from the bulb. Most run horizontally, either underground or along the surface of the ground under leaf litter. Flowering plants often produce no stolons. A number of bulbous forming species produce stolons with
Erythronium propullans producing one stolon below the soil surface on the midway point of the stem on blooming plants that produces a new
bulbA bulb is an underground vertical shoot that has modified leaves that are used as food storage organs by a dormant plant....
. On non blooming plants 1 to 3 stolons are produce directly from the bulbs, each ending in a new
cloneCloning in biology is the process of producing populations of genetically-identical individuals that occurs in nature when organisms such as bacteria, insects or plants reproduce asexually. Cloning in biotechnology refers to processes used to create copies of DNA fragments , cells , or organisms...
.
Convolvulus arvensisConvolvulus arvensis is a species of bindweed, native to Europe and Asia. It is a climbing or creeping herbaceous perennial plant growing to 0.5-2 m high. The leaves are spirally arranged, linear to arrowhead-shaped, 2-5 cm long, with a 1-3 cm petiole...
is a weed species in agriculture that spreads by under ground stolons that produce rhizomes.
In studies on
grassGrasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns...
species, with plants that produce stolons or rhizomes and plants that produce both stolons and rhizomes; morphological and physiological differences where noticed. Stolons have longer internodes and function as means of seeking out light and were used for propagation of the plant, while rhizomes are used as storage organs for carbohydrates and the maintenance of meristem tissue to keep the parent plant alive from one year to the next.
Mycology
In
mycologyMycology is the branch of biology concerned with the study of fungi, including their genetic and biochemical properties, their taxonomy, and their use to humans as a source for tinder, medicinals , food , entheogens, as well as their dangers, such as poisoning or infection.From...
, a stolon is defined as an occasionally septate hyphae, which connect sporangiophores together. Root-like structures called rhizoids may appear on the stolon as well, anchoring the hyphae to the
substrateIn biology a substrate is the surface a plant or animal lives upon. The substrate can include biotic or abiotic materials. For example, encrusting algae that lives on a rock can be substrate for another animal that lives above the algae on the rock. See also substrate .-External links:*...
. The stolon is commonly found in bread molds, and are seen as horizontally expanding across the mold.
Zoology
Some bryozoans form colonies through connection of individual units by stolons. Other colonies include sheets and erect colonies.