Editing Bud

{{short description|Immature or embryonic shoot}}
{{Redirect|1=Flower bud|2=EP of GFriend|3=Flower Bud}}
{{For|usage in [[asexual reproduction]]|Budding}}
{{Other uses}}
[[File:Fagus sylvatica bud.jpg|thumb|upright=1.35|[[European beech]] (''Fagus sylvatica'') 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]] condition, or it may form a shoot immediately. Buds may be specialized to develop [[flower]]s or short shoots or may have the potential for general shoot development. The term bud is also used in [[zoology]], where it refers to an outgrowth from the body which can develop into a new individual.

==Overview==
[[File:Halesia carolina, skubblare, Manie van der Schijff BT, a.jpg|thumb|right|[[Inflorescence]] bud scales in ''[[Halesia carolina]]'']]
The buds of many [[woody plant]]s, especially in temperate or cold climates, are protected by a covering of modified leaves called ''scales'' which tightly enclose the more delicate parts of the bud. Many bud scales are covered by a gummy substance which serves as added protection. When the bud develops, the scales may enlarge somewhat but usually just drop off, leaving a series of horizontally-elongated [[scar]]s on the surface of the growing stem. By means of these scars one can determine the age of any young branch, since each year's growth ends in the formation of a bud, the formation of which produces an additional group of bud scale scars. Continued growth of the branch causes these scars to be obliterated after a few years so that the total age of older branches cannot be determined by this means.{{citation needed|date=February 2023}}

In many plants, scales do not form over the bud, and the bud is then called a naked bud.<ref>Walters, Dirk R., and David J. Keil. 1996. ''Vascular plant taxonomy''. Dubuque, Iowa: Kendall/Hunt Pub. Co. page 598.</ref> The minute underdeveloped leaves in such buds are often excessively hairy. Naked buds are found in some shrubs, like some species of the [[Sumac]] and [[Viburnum]]s (''Viburnum alnifolium'' and ''V. lantana'')<ref>Cronquist, Arthur, and Henry A. Gleason. 1991. ''Manual of Vascular Plants of Northeastern United States and Adjacent Canada''. Bronx, New York: New York Botanical Garden Press. page 512.</ref> and in [[herbaceous]] plants. In many of the latter, buds are even more reduced, often consisting of undifferentiated masses of cells in the axils of leaves. A terminal bud occurs on the end of a stem and lateral buds are found on the side. A head of [[cabbage]] (see [[Brassica]]) is an exceptionally large terminal bud, while [[Brussels sprout]]s are large lateral buds.{{citation needed|date=February 2023}}

Since buds are formed in the axils of leaves, their distribution on the stem is the same as that of leaves. There are alternate, opposite, and whorled buds, as well as the terminal bud at the tip of the stem. In many plants buds appear in unexpected places: these are known as adventitious buds.<ref>Coulter, John G. 1913.'' Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany''. New York: American book company. page 188</ref>

Often it is possible to find a bud in a remarkable series of gradations of bud scales. In the [[Aesculus|buckeye]], for example, one may see a complete gradation from the small brown outer scale through larger scales which on unfolding become somewhat green to the inner scales of the bud, which are remarkably leaf-like. Such a series suggests that the scales of the bud are in truth leaves, modified to protect the more delicate parts of the plant during unfavorable periods.{{cn|date=June 2024}}

==Types of buds==
[[File:Plant Buds clasification.svg|thumb|right|Plant buds classification]]
[[File:Ficus bud.JPG|thumb|right|Terminal, vegetative bud of ''[[Ficus carica]]'']]
Buds are often useful in the identification of plants, especially for woody plants in winter when leaves have fallen.<ref>{{citation |author=Trelease, W. |orig-year=1931|year= 1967 |title=Winter botany: An Identification Guide to Native Trees and Shrubs |publisher=Dover Publications, Inc |location=New York |isbn=0486218007 }}</ref> Buds may be classified and described according to different criteria: location, status, morphology, and function.{{cn|date=June 2024}}

Botanists commonly use  the following terms:
* for location:{{citation needed|date=February 2023}}
** '''{{vanchor|terminal}}''', when located at the tip of a stem  ('''apical''' is equivalent but rather reserved for the one at the top of the plant);
** '''[[Axillary bud|axillary]]''', when located in the axil of a leaf ('''lateral''' is the equivalent but some adventitious buds may be lateral too);
** '''[[Adventitiousness#Adventitious buds and shoots|adventitious]]''', when located elsewhere, for example on the trunk or roots (some adventitious buds may be former axillary ones that are reduced and hidden under the bark, while other adventitious buds are completely new formed ones).
* for status:{{citation needed|date=November 2023}}
** '''accessory''', for secondary buds formed besides a principal  bud (axillary or terminal);
** '''resting''', for a bud that forms at the end of a growth season, and then lies dormant until the onset of the next growth season;
** '''dormant''' or '''latent''', for buds whose growth has been delayed for a rather long time. The term is usable as a synonym of ''resting'', but is better employed for buds waiting undeveloped for years, for example '''[[Epicormic shoot#Epicormic buds|epicormic buds]]''';
** '''pseudoterminal''', for an axillary bud taking over the function of a terminal bud (characteristic of species whose growth is [[sympodial]]: terminal  bud dies and is replaced by the closer axillary bud, for examples [[beech]], [[persimmon]], ''[[Platanus]]'' have sympodial growth).
* for morphology:
** '''scaly''' or '''covered''' ('''perulate'''), when scales, also referred to as a perule (lat. perula, perulaei) (which are in fact transformed and reduced leaves) cover and protect the embryonic parts;
** '''naked''', when not covered by scales;
** '''hairy''', when also protected by hairs (it may apply either to scaly or to naked buds).
* for function:{{citation needed|date=November 2023}}
** '''vegetative''', only containing vegetative structures: a '''leaf bud''' is an embryonic shoot containing leaves;
** '''reproductive''', only containing embryonic flower(s): a '''flower bud''' contains a single [[flower]] while an '''inflorescence bud''' contains an [[inflorescence]];
** '''mixed''', containing both embryonic leaves and flower(s).

===Image gallery===
<gallery mode="packed" heights="154px" caption="Buds">
File:Alnus glutinosa bud 2.jpg|''[[Alnus glutinosa]]'' bud
File:Tilia platyphallos bud.jpg|''[[Tilia platyphyllos|Tilia]]'' bud
File:Buds of Fraxinus excelsior 03.jpg|Black buds of a European ash, ''[[Fraxinus excelsior]]''
File:Quince Blossom with removed watermark.jpg|A [[quince]]'s flower bud with spirally folded petals
File:Nelumbo nucifera, also known as Indian lotus in bud stage (Image 7 of 7).jpg|Opening ''[[Nelumbo]]'' flower bud
File:Coreopsis tinctoria cultivar Uptick Cream and Red 8.JPG|Opening ''[[Coreopsis tinctoria]]'' flower buds
File:Vitis vinifera - bud0.jpg|''[[Vitis vinifera]]'' flower buds
File:烏材（軟毛柿）Diospyros eriantha 20210331093242 04.jpg|''[[Diospyros eriantha]]'' bud
File:Flower bud of Sunflower - Helianthus.JPG|Inflorescence bud of the [[common sunflower]] (''Helianthus annuus'')
File:Acanthus balcanicus.jpg|Inflorescence bud of ''[[Acanthus balcanicus]]''
File:Banksia sessilis inflorescence bud closed.jpg|Inflorescence bud of the parrot bush (''[[Banksia sessilis]]'')
File:Cynara cardunculus0.jpg|Inflorescence bud of [[cardoon]] (''Cynara cardunculus'')
File:Bud1web.jpg|An opening inflorescence bud at left, which will develop like the one to its right
</gallery>

== References ==
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[[Category:Plant physiology]]
[[Category:Plant morphology]]