An epicormic shoot is a shoot growing from an epicormic bud, which lies underneath the

bark Bark may refer to: Common meanings * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Arts and entertainment * ''Bark'' (Jefferson Airplane album), ...

of a trunk,

stem Stem or STEM most commonly refers to: * Plant stem, a structural axis of a vascular plant * Stem group * Science, technology, engineering, and mathematics Stem or STEM can also refer to: Language and writing * Word stem, part of a word respon ...

, or

branch A branch, also called a ramus in botany, is a stem that grows off from another stem, or when structures like veins in leaves are divided into smaller veins. History and etymology In Old English, there are numerous words for branch, includ ...

of a

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

. Epicormic buds lie dormant beneath the bark, their growth suppressed by hormones from active shoots higher up the plant. Under certain conditions, they grow into active shoots, such as when damage occurs to higher parts of the plant, or light levels are increased following removal of nearby plants. Epicormic buds and shoots occur in many woody species, but are absent from many others, such as most

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 division contains a sin ...

Function

Human

horticultural Horticulture (from ) is the art and science of growing fruits, vegetables, flowers, trees, shrubs and ornamental plants. Horticulture is commonly associated with the more professional and technical aspects of plant cultivation on a smaller and mo ...

practices that exploit epicormic growth rely on plants that have epicormic budding capabilities for regenerative function in response to

crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, parti ...

damage, such as through

wind Wind is the natural movement of atmosphere of Earth, air or other gases relative to a planetary surface, planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heatin ...

fire Fire is the rapid oxidation of a fuel in the exothermic chemical process of combustion, releasing heat, light, and various reaction Product (chemistry), products. Flames, the most visible portion of the fire, are produced in the combustion re ...

. Epicormic shoots are the means by which trees regrow after

coppicing Coppicing is the traditional method in woodland management of cutting down a tree to a tree stump, stump, which in many species encourages new Shoot (botany), shoots to grow from the stump or roots, thus ultimately regrowing the tree. A forest ...

pollarding Pollarding is a pruning system involving the removal of the upper branches of a tree, which promotes the growth of a dense head of foliage and branches. In ancient Rome, Propertius mentioned pollarding during the 1st century BCE. The practice h ...

, where the tree's trunk or branches are cut back on a regular cycle. These

forestry Forestry is the science and craft of creating, managing, planting, using, conserving and repairing forests and woodlands for associated resources for human and Natural environment, environmental benefits. Forestry is practiced in plantations and ...

techniques cannot be used on species which do not possess strong epicormic growth abilities. Pruning leads to growth of suppressed shoots below the cut – these may be from epicormic buds, but they may also be other growth, such as normal

bud In botany, a bud is an undeveloped or Plant embryogenesis, embryonic Shoot (botany), shoot and normally occurs in the axil of a leaf or at the tip of a Plant stem, stem. Once formed, a bud may remain for some time in a dormancy, dormant conditi ...

s or small shoots which are only partly suppressed.

Examples

Epicormic resprouting is typical of some tree species from fire-prone ecosystems. Epicormic shoot on Callistemon showing fragile attachment IMG 5058-63L

Epicormic shoot on Callistemon showing fragile attachment IMG 5058-63L

As one of their responses to frequent

bushfires A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a ...

which would destroy most other plants, many

Eucalypt Eucalypt is any woody plant with Capsule (fruit), capsule fruiting bodies belonging to one of seven closely related genera (of the tribe Eucalypteae) found across Australia: ''Eucalyptus'', ''Corymbia'', ''Angophora'', ''Stockwellia'', ''Allosyn ...

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

s found widely throughout

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

have extensive epicormic buds which sprout following a fire, allowing the vegetative regeneration of branches from their trunks. These epicormic buds are highly protected, set deeper beneath the thick bark than in other tree species, allowing both the buds and

vascular cambium The vascular cambium is the main growth tissue in the stems and roots of many plants exhibiting secondary growth, specifically in dicots such as buttercups and oak trees, gymnosperms such as pine trees, as well as in certain other vascular ...

to be insulated from the intense heat. Not all eucalypt trees possess this means of vegetative recovery, and the ability of a tree to survive and re-sprout depends on many factors, such as fire intensity, scorch height, and tree height, species, age, and size. Jarrah trees, found in the south-west of

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

, have epicormic buds which are activated after a bushfire or other extreme conditions. The Mediterranean '' Quercus suber'' (cork oak) resprouts from epicormic buds after fire.

Dogwood ''Cornus'' is a genus of about 30–60 species of woody plants in the family Cornaceae, commonly known as dogwoods or cornels, which can generally be distinguished by their blossoms, berries, and distinctive bark. Most are deciduous ...

trees which are susceptible to a

fungal A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as one of the tradit ...

infection known as dogwood anthracnose ('' Discula destructiva'') will sometimes send out epicormic shoots when they are dying from the disease. Similarly, ash trees may develop epicormic shoots when infested by the emerald ash borer. Epicormic shoots can be used in mass propagation of

oak An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...

trees. The long-lived '' Pseudotsuga macrocarpa'' (bigcone Douglas fir) forms epicormic shoots both in response to fire damage and as a means of forming growth on existing branches. The epicormic branching pattern has been observed to six iterations. Pseudotsuga macrocarpa LytleCreek2

References

External links

Epicormic roots on a Norway Maple video

Epicormic shoots on oak, alder and larch
{{DEFAULTSORT:Epicormic Shoot Horticulture

Function

Examples

See also

References

External links