Dehiscence is the splitting of a mature plant structure along a built-in line of weakness to release its contents. This is common among fruits , anthers and sporangia . Sometimes this involves the complete detachment of a part. Structures that open in this way are said to be dehiscent . Structures that do not open in this way are called indehiscent , and rely on other mechanisms such as decay or predation to release the contents.
27-554: [REDACTED] Look up mugunghwa in Wiktionary, the free dictionary. Mugunghwa may refer to: Hibiscus syriacus , the national flower of South Korea Mugunghwa-ho , a class of train Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Mugunghwa . If an internal link led you here, you may wish to change
54-760: A day. However, numerous buds produced on the shrub's new growth provide prolific flowering over a long summer blooming period. The soil in which the Hibiscus thrives is moist but well-drained, and organically rich. Hibiscus syriacus is highly tolerant of air pollution, heat, humidity, poor soil and drought. The species has naturalized very well in many suburban areas and might even be termed slightly invasive , so frequently does it seed. The branches are thin and gray, white- lenticeled , with raised leaf scars and small buds. Stems and branches do not branch very much unless pruned, resulting in many long, straight stems that originate from about 1.5–4 cm (0.5–1.5 inches) above
81-400: A different colored throat, depending upon the cultivar. Extending from the base of these five petals is the pistil at the center, with the stamen around it. These basic characteristics give the H. syriacus flower and its many variants their distinctive form. The plant can bloom continuously from July through September, usually at night. With maturity, flexible plant stems become weighted under
108-418: A horizontal opening that causes a lid to separate completely. This type of dehiscence occurs in some fruit and anthers and also in some flower buds. Anther dehiscence is the final function of the anther that causes the release of pollen grains. This process is coordinated precisely with pollen differentiation, floral development, and flower opening. The anther wall breaks at a specific site. Usually this site
135-413: A popular ornamental shrub today, with many cultivars . Full-grown plants can tolerate a wide range of conditions, including frost, drought and urban pollution. However, the best results are produced in a warm, sheltered position; a well-drained neutral soil ; and full sun. Hibiscus syriacus is fairly easily propagated from either seeds , with variable results, or by layering or cuttings , cloning
162-592: A small hole (pore) is referred to as poricidal dehiscence. The pore may have a cover ( operculate poricidal dehiscence or operculate dehiscence ) that is referred to as an operculum or it may not ( inoperculate poricidal dehiscence or inoperculate dehiscence ). Poricidal dehiscence occurs in many unrelated organisms, in fruit, causing the release of seeds, and also in the sporangia of many organisms (flowering plants, ferns, fungi, slime molds ). Poricidal anthers of various flowers are associated with buzz pollination by insects. Circumscissile dehiscence involves
189-415: Is dehiscence that occurs upon wetting, the fruit being hygroscopic . Dehiscent fruits that are derived from one carpel are follicles or legumes , and those derived from multiple carpels are capsules or siliques . One example of a dehiscent fruit is the silique . This fruit develops from a gynoecium composed of two fused carpels , which, upon fertilization, grow to become a silique that contains
216-412: Is observed as an indentation between the locules of each theca and runs the length of the anther, but in species with poricidal anther dehiscence it is instead a small pore. If the pollen is released from the anther through a split on the outer side (relative to the center of the flower), this is extrorse dehiscence, and if the pollen is released from the inner side, this is introrse dehiscence. If
243-422: Is rarely referred to as dehiscence unless circumscissile dehiscence is involved; anthesis is the usual term for the opening of flowers. Dehiscence may or may not involve the loss of a structure through the process of abscission . The lost structures are said to be caducous . Manipulation of dehiscence can improve crop yield since a trait that causes seed dispersal is a disadvantage for farmers, whose goal
270-437: Is responsible for the tensions that lead to splitting of the anther. This tissue is usually one to several layers thick, with cells walls of uneven thickness due to uneven lignification . The cells lose water, and the uneven thickness causes the thinner walls of the cells to stretch to a greater extent. This creates a tension that eventually leads to the anther being split along its line of weakness and releasing pollen grains to
297-436: Is to collect the seed. Many agronomically important plants have been bred for reduced shattering . Explosive dehiscence is a ballistic form of dispersal that flings seeds or spores far from the parent plant. This rapid plant movement can achieve limited dispersal without the assistance of animals. A notable example is the sandbox tree ( Hura crepitans ), which can fling seeds 100 meters (300 ft) and has been called
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#1732779631546324-609: The United Kingdom ). It is the national flower of South Korea and is mentioned in the South Korean national anthem . Hibiscus syriacus is a hardy deciduous shrub. It is upright and vase-shaped, reaching 2–4 m (7–13 feet) in height, bearing large trumpet-shaped flowers with prominent yellow-tipped white stamens . The flowers are often pink in color, but can also be dark pink (almost purple), light pink or white. Individual flowers are short-lived, lasting only
351-434: The replum (the persisting septa of the ovary). At maturity, the dehiscence zone is effectively a non-lignified layer between two regions of lignified cells in the valve and the replum. Shattering occurs due to the combination of cell wall loosening in the dehiscence zone and the tensions established by the differential hygro-responsive properties of the drying cells. Endothecium tissue found in moss capsules functions in
378-460: The "boomer plant" due to the loud sound it generates. Another example is Impatiens , whose explosive dehiscence is triggered by being touched, leading it to be called the "touch-me-not". Ecballium elaterium , the "squirting cucumber", uses explosive dehiscence to disperse its seeds, ejecting them from matured fruit in a stream of mucilaginous liquid. Explosive dehiscence of sporangia is a characteristic of Sphagnum . In loculicidal dehiscence,
405-578: The 1st century. Its leaves were brewed into a herbal infusion and its flowers eaten in Korea. Later on it was introduced and grown in the gardens of Europe as early as the 16th century, though as late as 1629 John Parkinson thought it was tender and took great precautions with it, thinking it "would not suffer to be uncovered in the Winter time, or yet abroad in the Garden, but kept in a large pot or tubbe in
432-605: The Korean rose, is the national flower of South Korea . The flower appears in various national emblems , and Korea is compared poetically to the flower in the South Korean national anthem . The flower's name in Korean is mugunghwa ( Korean : 무궁화 ; Hanja : 無窮花 ), which translates to “eternal blossom that never fades”. It is also known as mokkeunhwa ( 목근화 ; 木槿花 ). Professor emeritus at Ohio State University , Chan E. Park, notes that, to many Koreans,
459-418: The atmosphere. Flower buds of Eucalyptus and related genera open with circumscissile dehiscence. A small cap separates from the remainder of the bud along a circular horizontal zone. There are many different types of fruit dehiscence involving different types of structures. Some fruits are indehiscent, and do not open to disperse the seeds. Xerochasy is dehiscence that occurs upon drying, and hygrochasy
486-411: The developing seeds . After seed maturation, dehiscence takes place, and valves detach from the central septum , thus freeing the seeds. This is also known as shattering and can be important as a seed dispersal mechanism. This process is similar to anther dehiscence and the region that breaks (dehiscence zone) runs the entire length of the fruit between the valves (the outer walls of the ovary) and
513-486: The flower was a symbol of resistance to Japanese colonial rule . South Korean law also defined the flagpole used for hoisting national flag should be surmounted by a ball that has the shape of the flower's calyx. Hibiscus syriacus was originally endemic to Korea. It was brought to Japan in the 8th century and cultivated for horticulture. According to records, it was prolific on the Korean Peninsula before
540-510: The ground, giving rise to the shrub's overall vase shape. The leaves appear unusually late in the season, in May. They are usually green or yellowish green, alternate, broadly ovate, palmately veined, and 7.5 cm (3 inches) long. They have three distinct lobes with coarsely-toothed margins. Hibiscus syriacus has 5-petaled flowers (to 7.5 cm or 3 inches diameter) in solid colors of white, red, purple, mauve, violet, or blue, or bicolors with
567-688: The house or in a warme cellar, if you would have them to thrive." ( sic ) By the end of the 17th century, some knew it to be hardy: Gibson, describing Lord Arlington's London house noted six large earthen pots coddling the "tree hollyhock", as he called it, "that grows well enough in the ground". By the 18th century the shrub was common in English gardens and in the North American colonies, known as Althea frutex and "Syrian ketmia". Dehiscent A similar process to dehiscence occurs in some flower buds (e.g., Platycodon , Fuchsia ), but this
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#1732779631546594-425: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Mugunghwa&oldid=1206913910 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Hibiscus syriacus Hibiscus syriacus is a species of flowering plant in
621-527: The load of prolific summer flowers, and bend over halfway to the ground. Most modern cultivars are virtually fruitless. The fruits of those that have them are green or brown, unornamental 5-valved dehiscent capsules, which persist throughout much of the winter. They split over the course of the dormant season and spread their easily germinating seeds around the base of the parent plant, thus forming colonies with time. Though it has no fall color and can be stiff and ungainly if badly pruned, H. syriacus remains
648-476: The locule wall splits between the septa, leaving the latter intact, while in septicidal dehiscence the split is at the septum that separates the loculi. Septicidal and loculicidal dehiscence may not be completely distinct; in some cases both the septa and the walls of the locules split. Dehiscence occurs through breakage of various parts of the enclosing structure; the mechanisms can be classified in various ways, but intermediate forms also occur. Dehiscence through
675-521: The mallow family, Malvaceae . It is native to areas of east Asia , but widely introduced elsewhere, including much of Europe and North America . It was given the epithet syriacus because it had been collected from gardens in Syria . Common names include the rose of Sharon , (especially in North America ), Syrian ketmia , shrub althea (or simply althea ), and rose mallow (in
702-540: The original. Old shrubs can develop trunk cankers that may eventually prove fatal to the plant. The plant has some susceptibility to leaf spots , blights , rusts and canker. Japanese beetles , whiteflies and aphids are occasional insect visitors. Japanese beetles can severely damage foliage if left unchecked. The following cultivars have gained the Royal Horticultural Society 's Award of Garden Merit : Hibiscus syriacus , also known as
729-470: The pollen is released through a split that is positioned to the side, towards other anthers, rather than towards the inside or outside of the flower, this is latrorse dehiscence. The stomium is the region of the anther where dehiscence occurs. The degeneration of the stomium and septum cells is part of a developmentally timed cell-death program. Expansion of the endothecial layer and subsequent drying are also required for dehiscence. The endothecium tissue
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