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botany Botany, also called plant science (or plant sciences), 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 "bot ...
, a bract is a modified or specialized
leaf A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
, especially one associated with a reproductive structure such as a
flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanism ...
,
inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed ...
axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture. Typically, they also look different from the parts of the flower, such as the petals or
sepals A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...
. A plant having bracts is referred to as bracteate or bracteolate, while one that lacks them is referred to as ebracteate and ebracteolate, without bracts.


Variants

Some bracts are brightly-coloured and serve the function of attracting pollinators, either together with the
perianth The perianth (perigonium, perigon or perigone in monocots) is the non-reproductive part of the flower, and structure that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla (petals) or tepals when ca ...
or instead of it. Examples of this type of bract include those of '' Euphorbia pulcherrima'' (poinsettia) and ''
Bougainvillea ''Bougainvillea'' ( , ) is a genus of thorny ornamental vines, bushes, and trees belonging to the four o' clock family, Nyctaginaceae. It is native to eastern South America, found from Brazil, west to Peru, and south to southern Argentina. ...
'': both of these have large colourful bracts surrounding much smaller, less colourful flowers. In
grasses Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns a ...
, each floret (flower) is enclosed in a pair of papery bracts, called the lemma (lower bract) and palea (upper bract), while each spikelet (group of florets) has a further pair of bracts at its base called glumes. These bracts form the chaff removed from
cereal A cereal is any grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, germ, and bran. Cereal grain crops are grown in greater quantities and provide more foo ...
grain during threshing and winnowing. Bats may detect acoustic signals from dish-shaped bracts such as those of '' Marcgravia evenia''. A prophyll is a leaf-like structure, such as a bracteole, subtending (extending under) a single flower or pedicel. The term can also mean the lower bract on a
peduncle Peduncle may refer to: *Peduncle (botany), a stalk supporting an inflorescence, which is the part of the shoot of seed plants where flowers are formed *Peduncle (anatomy), a stem, through which a mass of tissue is attached to a body **Peduncle (art ...
. The frequently showy pair of bracts of ''
Euphorbia ''Euphorbia'' is a very large and diverse genus of flowering plants, commonly called spurge, in the family Euphorbiaceae. "Euphorbia" is sometimes used in ordinary English to collectively refer to all members of Euphorbiaceae (in deference to t ...
'' species in subgenus ''Lacanthis'' are the cyathophylls. Bracts subtend the cone scales in the seed cones of many
conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All ex ...
s, and in some cases, such as ''
Pseudotsuga ''Pseudotsuga'' is a genus of evergreen coniferous trees in the family Pinaceae (subfamily Laricoideae). Common names for species in the genus include Douglas fir, Douglas-fir, Douglas tree, Oregon pine and Bigcone spruce. ''Pseudotsuga menzie ...
'', they extend beyond the cone scales. File:Castilleja levisecta bracts.jpg, Bright yellow bracts of '' Castilleja levisecta'' are more tightly pressed against the stem than bracts of other '' Castilleja'' species. File:Bougainvillea glabra.JPG, Bracts of '' Bougainvillea glabra'', differ in colour from the non-bract leaves, and attract pollinators. File:Banana bract.jpg, Bracts along a
banana A banana is an elongated, edible fruit – botanically a berry (botany), berry – produced by several kinds of large herbaceous flowering plants in the genus ''Musa (genus), Musa''. In some countries, Cooking banana, bananas used for ...
flower stalk surround the rows of flowers File:E milii vulcanii ies.jpg, '' Euphorbia milii'' var. ''vulcanii'' cyathia bearing a pair of pinkish cyathophylls. File:Ananas bracteatus var tricolor.jpg, Colourful bracts of '' Ananas bracteatus''. File:Erigeron peregrinus 6287.JPG, The many green
involucral bract In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or o ...
s of '' Erigeron peregrinus'' are linear, loose, taper to a point, about the same length, and help to distinguish this species. File:Blooming Dogwood.jpg, Dogwood species '' Cornus florida'' inflorescence showing four large white bracts and central flower cluster. File:2013-05-10 08 26 08 Closeup of pink dogwoods at the Brendan T. Byrne State Forest headquarters.jpg, '' Cornus florida'' dogwood
cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture ...
with pink bracts surrounding small flower cluster. File:豔紅苞鳳梨 20190712192436.jpg, The red bracts of ''
Aechmea bracteata ''Aechmea bracteata'' is a plant species in the genus ''Aechmea''. This species is native to Central America, Mexico, Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions ...
''. File:女王鬱金 20190715203108 01.jpg, The pink bracts of ''
Curcuma petiolata ''Curcuma petiolata'' (also known as jewel of Thailand, Siam tulip, hidden ginger, pastel hidden ginger, hidden lily or queen lily) is a plant of the Zingiberaceae or ginger family. It is native to Thailand, Myanmar, Laos and Java. Average he ...
''. File:火鶴 20190729181532.jpg, The pink bract of a new cultivar: ''
Anthurium andraeanum ''Anthurium andraeanum'' is a flowering plant species in the family Araceae that is native to Colombia and Ecuador. A winner of the Royal Horticultural Society's Award of Garden Merit, it is one of the plants listed in the NASA Clean Air Study, ...
'' 'Pink Lady'. File:豔山姜花序總苞 20190508131956.jpg, The inflorescence of '' Alpinia zerumbet'' protected by two bracts before flower bloom. File:地湧金蓮 Musella lasiocarpa 20201028130818 01.jpg, The golden bracts of '' Musella lasiocarpa''. File:Hydrangea involucrata (9344379310).jpg, Large bracts of '' Hydrangea involucrata'' surround tiny flowers and demonstrate the "lacecap" style
inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed ...
that has made various ''
Hydrangea ''Hydrangea'', () commonly named the hortensia, is a genus of over 75 species of flowering plants native to Asia and the Americas. By far the greatest species diversity is in eastern Asia, notably China, Korea, and Japan. Most are shrubs tall ...
'' species and
cultivars A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture ...
popular with gardeners. File:Viburnum opulus RF.jpg, Like many ''
Hydrangea ''Hydrangea'', () commonly named the hortensia, is a genus of over 75 species of flowering plants native to Asia and the Americas. By far the greatest species diversity is in eastern Asia, notably China, Korea, and Japan. Most are shrubs tall ...
'' species ( Hydrangeaceae family), '' Viburnum opulus'' ( Adoxaceae family) has bracts that surround tiny flowers, creating a "lacecap" style
inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed ...
.


Bracteole

A small bract is called a bracteole or bractlet. Technically this is any bract that arises ''on'' a pedicel instead of subtending it.


Involucral bracts

Bracts that appear in a
whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane flo ...
subtending an
inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed ...
are collectively called an involucre. An involucre is a common feature beneath the inflorescences of many
Apiaceae Apiaceae or Umbelliferae is a family of mostly aromatic flowering plants named after the type genus '' Apium'' and commonly known as the celery, carrot or parsley family, or simply as umbellifers. It is the 16th-largest family of flowering plant ...
,
Asteraceae The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae ...
, Dipsacaceae and Polygonaceae. Each flower in an inflorescence may have its own whorl of bracts, in this case called an involucel. In this case they may be called ''chaff'', ''paleas'', or ''receptacular bracts'' and are usually minute scales or bristles. Many asteraceous plants have bracts at the base of each inflorescence. The term involucre is also used for a highly conspicuous bract or bract pair at the base of an inflorescence. In the family
Betulaceae Betulaceae, the birch family, includes six genera of deciduous nut-bearing trees and shrubs, including the birches, alders, hazels, hornbeams, hazel-hornbeam, and hop-hornbeams numbering a total of 167 species. They are mostly natives of ...
, notably in the genera '' Carpinus'' and ''
Corylus The hazel (''Corylus'') is a genus of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family Betulaceae,Germplasmgobills Information Network''Corylus''Rushforth, K. (19 ...
'', the involucre is a leafy structure that protects the developing nuts. Beggar-tick ('' Bidens comosa'') has narrow involucral bracts surrounding each inflorescence, each of which also has a single bract below it. There is then a pair of leafy bracts on the main stem and below those a pair of leaves.


Epicalyx

An epicalyx, which forms an additional whorl around the
calyx Calyx or calyce (plural "calyces"), from the Latin ''calix'' which itself comes from the Ancient Greek ''κάλυξ'' (''kálux'') meaning "husk" or "pod", may refer to: Biology * Calyx (anatomy), collective name for several cup-like structures ...