In botany Botany, plant science, phytology, or plant biology is a branch of biology that involves the scientific study of plant life. Botany covers a wide range of scientific disciplines concerned with the study of plants, algae and fungi, including structure, growth, reproduction, metabolism, development, diseases, chemical properties, and evolutionary, a bract is a modified or specialized leaf In botany, a leaf is an above-ground plant organ specialized for photosynthesis. For this purpose, a leaf is typically flat and thin. As an evolutionary trait, the flatness of leaves works to expose the chloroplasts to more light and to increase the absorption of carbon dioxide at the expense of water loss. In the Devonian period, when carbon, 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 . The biological function of a flower is to mediate the union of male sperm with female ovum in order to produce seeds. The process begins with pollination, is followed by fertilization, leading to the formation and dispersal of the seeds. For, 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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified. The modifications can involve the length and the nature of the internodes and the axis, or cone scale. Bracts are often (but not always) different from foliage leaves, for example being smaller, larger, or of a different color or texture.
Some bracts are brightly colored and serve the function of attracting pollinators, either in concert with or instead of the perianth A petal is one member or part of the corolla of a flower. The corolla is the name for all of the petals of a flower. The corolla (petals) and calyx (the name for all the sepals) make up the outer whorls of a flower; these form what is known as the perianth, which is used to attract pollinators based on its bright color. The term "tepal". An excellent example of this latter type of bract occurs in the Poinsettia Euphorbia pulcherrima, commonly known as poinsettia, is a species of flowering plant indigenous to Mexico and Central America. The name "poinsettia" is after Joel Roberts Poinsett, the first United States Minister to Mexico, who introduced the plant into the US in 1828. It is also called the Atatürk flower plant (Euphorbia pulcherrima), which has small green flowers, surrounded by large scarlet bracts.
A small bract is called a bracteole or bractlet. Technically this is any bract that arises on a pedicel instead of subtending it.
In grasses, 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 Chaff is the inedible, dry, scaly protective casings of the seeds of cereal grain, or similar fine, dry, scaly plant material such as scaly parts of flowers, or finely chopped straw. In agriculture chaff is used as livestock fodder, or is a waste material ploughed into the soil or burnt removed from cereal Cereals, grains, or cereal grains are grasses cultivated for the edible components of their fruit seeds (botanically, a type of fruit called a caryopsis): the endocarp, germ, and bran. Cereal grains are grown in greater quantities and provide more food energy worldwide than any other type of crop; they are therefore staple crops. In their natural grain during threshing Threshing is the process of loosening the edible part of cereal grain from the scaly, inedible chaff that surrounds it. It is the step in grain preparation after harvesting and before winnowing, which separates the loosened chaff from the grain. Threshing does not remove the bran from the grain and winnowing Wind winnowing is an agricultural method developed by ancient cultures for separating grain from chaff. It is also used to remove weevils or other pests from stored grain. Threshing, the separation of grain or seeds from the husks and straw, is the step in the chaff-removal process that comes before winnowing. "Winnowing the chaff" is a.
Bracts that appear in a whorl subtending an inflorescence are collectively called an involucre. An involucre is a common feature beneath the inflorescences of many Apiaceae The Apiaceae or Umbelliferae is a family of usually aromatic plants with hollow stems, commonly known as umbellifers. It includes angelica, anise, arracacha, asafoetida, caraway, carrot, celery, centella asiatica, chervil, cicely, coriander/cilantro, cumin, dill, fennel, hemlock, lovage, Queen Anne's Lace, parsley, parsnip, sea holly, the now, Asteraceae The Asteraceae or Compositae, also referred to as the aster, daisy, or sunflower family, is the largest family of vascular plants. The family has more than 22,750 currently accepted species, spread across 1620 genera, and 12 subfamilies. The largest genera are Senecio , Vernonia (1,000 species), Cousinia (600 species) and Centaurea (600 species), Dipsacaceae and Polygonaceae. Each flower in an inflorescence may have its own whorl of bracts, in this case called an involucel. In addition to these, many asteraceous The Asteraceae or Compositae, also referred to as the aster, daisy, or sunflower family, is the largest family of vascular plants. The family has more than 22,750 currently accepted species, spread across 1620 genera, and 12 subfamilies. The largest genera are Senecio , Vernonia (1,000 species), Cousinia (600 species) and Centaurea (600 species) plants also have bracts at the base of each flower. In this case the bracts at the base of the inflorescence or head The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization (involucral bracts or phyllaries) are scales or leaf-like structures, while those at the flower base (chaff, paleas or receptacular bracts) are usually minute scales or bristles.
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 Euphorbia is a genus of plants belonging to the family Euphorbiaceae. Consisting of about 2160 species, Euphorbia is one of the most diverse genera in the plant kingdom, maybe exceeded only by Senecio . Members of the family and genus are sometimes referred to as Spurges. Euphorbia antiquorum and Euphorbia serrata are the type species for the species in subgenus Lacanthis are the cyathophylls.
Bracts subtend the cone scales in the seed cones of many conifers The conifers, division Pinophyta, also known as division Coniferophyta or Coniferae, are one of 13 or 14 division level taxa within the Kingdom Plantae. Pinophytes are gymnosperms. They are cone-bearing seed plants with vascular tissue; all extant conifers are woody plants, the great majority being trees with just a few being shrubs. Typical, and in some cases, such as Pseudotsuga Douglas-fir is the English name applied in common to evergreen coniferous trees of the genus Pseudotsuga in the family Pinaceae. There are five species, two in western North America, one in Mexico, and two in eastern Asia. Nineteenth-century botanists had problems in classifying Douglas-firs, due to the species' similarity to various other, they extend beyond the cone scales, even in mature cones.
Spathe
Anthurium scherzerianum 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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified. The modifications can involve the length and the nature of the internodes and the with spathe and spadix In botany, a spadix is a type of spike: an inflorescence with small flowers crowded on a thickened, fleshy axis. The term is applied to certain monocotyledons, especially members of the Family Araceae called arums or aroids. In these flower heads there is typically also a spathe (from Ancient Greek spathe "broad blade") present: a large,A spathe is a large bract that forms a sheath to enclose the flower cluster of certain plants such as palms Arecaceae or Palmae , the palm family, is a family of flowering plants, the only family in the monocot order Arecales. There are roughly 202 currently known genera with around 2600 species, most of which are restricted to tropical, subtropical, and warm temperate climates. Most palms are distinguished by their large, compound, evergreen leaves, arums, and dayflowers. In many arums, the spathe is petal-like, attracting pollinators to the flowers arranged on a type of spike called a spadix In botany, a spadix is a type of spike: an inflorescence with small flowers crowded on a thickened, fleshy axis. The term is applied to certain monocotyledons, especially members of the Family Araceae called arums or aroids. In these flower heads there is typically also a spathe (from Ancient Greek spathe "broad blade") present: a large,.
Gallery
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Beggar-tick (Bidens comosa): narrow involucral bracts surround each inflorescence, each of which also has a single bract below it, then there is a pair of leafy bracts on the main stem and below those a pair of leaves. |
In Bougainvillea Bougainvillea is a genus of flowering plants native to South America from Brazil west to Peru and south to southern Argentina (Chubut Province). Different authors accept between four and 18 species in the genus. The plant was classified by Europeans in Brazil in 1768, by Philibert Commerçon, French Botanist accompanying French Navy admiral and each cluster of three flowers is surrounded by three or six colorful bracts |
Bright red bracts surrounding the inflorescence of poinsettia (Euphorbia pulcherrima) |
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Yellow petal-like bracts of Euphorbia epithymoides |
Euphorbia milii var. vulcanii cyathia bearing a pair of pinkish cyathophylls |
Green involucral bracts surrounding the bud of a sunflower Sunflowers are annual plants native to the Americas, that possess a large inflorescence (flowering head) (Helianthemum annuum) |
Showy white bracts of the Kousa Dogwood Cornus kousa |
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Large pink bracts of an Anthurium |
Colourful bracts of Ananas bracteatus |
Bract and spadix of Dracunculus vulgaris |
