Bract facts for kids
In botany, a bract is a modified leaf, especially one associated with a flower or inflorescence. Bracts are usually different from normal leaves. They may be smaller, larger, or of a different color, shape, or texture. Usually, they also look different from the parts of the flower, such as the petals and/or sepals.
Variants
Some bracts are brightly colored like petals, and attract pollinators like bees,. Examples of this type of bract include Euphorbia pulcherrima (poinsettia) and Bougainvillea: both of these have large colorful bracts surrounding much smaller, less colorful flowers.
In grasses, each floret (flower) is enclosed in a pair of papery bracts, while each spikelet (group of florets) has a further pair of bracts at its base called glumes. These bracts are the chaff removed from cereal grain during threshing and winnowing.
A prophyll is a leaf-like structure, such as a bracteole, subtending a single flower or pedicel. The term can also mean the lower bract on a peduncle.
The frequently showy pair of bracts of Euphorbia species in subgenus Lacanthis are the cyathophylls.
Bracts subtend the cone scales in the seed cones of many conifers, and in some cases, such as Pseudotsuga, they extend beyond the cone scales.
Bracts that appear in a whorl under an inflorescence are called an involucre. An involucre is a common feature beneath the inflorescences of many Apiaceae, Asteraceae, Dipsacaceae and Polygonaceae. Each flower in an inflorescence may have its own whorl of bracts. 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.
Epicalyx
An epicalyx, an additional whorl around the calyx of a single flower, is a modification of bracteoles. In other words, the epicalyx is a group of bracts resembling a calyx or bracteoles forming a whorl outer to the calyx. It is a calyx-like extra whorl of floral appendages. They are present in family Malvaceae, the Hibiscus family. Fragaria (strawberries) may or may not have an epicalyx.
Spathe
A spathe is a large bract that forms a sheath to enclose the flower cluster of certain plants such as palms, arums, and dayflowers. In many arums (Araceae family), the spathe is petal-like, attracting pollinators to the flowers arranged on a type of spike called a spadix.
Gallery
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Bracts of Bougainvillea glabra, differ in colour from the non-bract leaves, and attract pollinators
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Bracts along a banana flower stalk surround the rows of flowers
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Euphorbia milii var. vulcanii cyathia bearing a pair of pinkish cyathophylls
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Colourful bracts of Ananas bracteatus
Images for kids
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Beggar-tick (Bidens comosa)
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Bright yellow bracts of Castilleja levisecta are more tightly pressed against the stem than bracts of other Castilleja species.
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The many green involucral bracts of Erigeron peregrinus are linear, loose, taper to a point, about the same length, and help to distinguish this species.
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Dogwood species Cornus florida inflorescence showing four large white bracts and central flower cluster.
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Cornus florida dogwood cultivar with pink bracts surrounding small flower cluster.
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The red bracts of Aechmea bracteata.
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The pink bracts of Curcuma petiolata.
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The pink bract of a new cultivar: Anthurium andraeanum 'Pink Lady'.
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The inflorescence of Alpinia zerumbet protected by two bracts before flower bloom.
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The golden bracts of Musella lasiocarpa.
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Large bracts of Hydrangea involucrata surround tiny flowers and demonstrate the "lacecap" style inflorescence that has made various Hydrangea species and cultivars popular with gardeners.
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Like many Hydrangea species (Hydrangeaceae family), Viburnum opulus (Adoxaceae family) has bracts that surround tiny flowers, creating a "lacecap" style inflorescence.
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See also
In Spanish: Bráctea para niños
