Flower

Japanese: 花 - はな

Fern flower

Horsetail is a flower of Equisetum arvense, which is formed by the whorl of sporangiophores that bear sporangia, which are gathered together in a spike. In Polytrichum arvensis, leaflets bearing sporangia gather at the base of the upper surface to form a spike, but the sporangia differentiate into female megasporangia and male microsporangia, and the leaflets that bear them grow together in a single spike.

[Michio Tamura]

Gymnosperm Flower

In gymnosperms, the female megasporangium is enveloped by the integument to become an ovule, and the male microsporangium becomes a pollen sac.

[Michio Tamura]

Cycads and Ginkgos

In the Cycadaceae, pollen sacs are attached to the upper surface of the microsporophyll in groups of 3-4, and the ovules are attached to the lower edge of the megasporophyll. The microsporophyll is densely packed in a spike to produce male flowers, and the megasporophyll is loosely packed at the apex of the stem to produce female flowers. In the Ginkgoceae, pollen sacs are attached to the microsporophyll stipe in groups of 2, and these are then gathered in a spike to produce male flowers. The ovules are attached to the megasporophyll stipe in pairs, and the upper end of the ovule spreads out to form a cup shape and surrounds the base of the ovule. This cup shape sometimes spreads out to form a leaf shape (this is called "ginkgo with leaves"). For this reason, the cup shape is sometimes interpreted as a degenerated megasporophyll.

[Michio Tamura]

Coniferae

In the class Conifolia (Pinaceae), several pollen sacs usually grow on the underside of a scale, which then gather in a spike on the axis to become a male flower. The basic structure of male flowers can be considered to be almost uniform throughout the class Conifolia, but female flowers are extremely diverse. In most cases, ovules grow on the upper surface of the scale, which then gather in a spike on the axis to form a cone. In the family Cryptomeria, the scale that bears the ovule is simple, but in the family Pinaceae, there is another scale underneath, giving it a double structure. From an evolutionary perspective, cones originally had a more complex structure. In the Cordaites, which flourished in the Carboniferous Period of the Paleozoic Era, the axis of the cone had a bract (bract leaf), and the branches extending from the axils had leaves and ovules. It is believed that over time, the branches growing axillary from the bract degenerated, and the whole evolved in a direction that made it more cohesive as a spike. Therefore, even among modern plants, those with double cone scales, such as pine trees, are considered to be primitive, with the lower scales being the capsule and the upper scales bearing ovules being degenerate branches or related to them. And those with a single scale, such as cedar trees, are considered to be the fusion of the two. The number of scales that make up a cone has further decreased, and in the Podocarpus family, one cone is produced from one scale bearing an ovule.

[Michio Tamura]

Gnetum

In Gnetophyta, both male and female flowers are enclosed in a membranous perianth when young. In Ephedra, male inflorescences have 2-8 pairs of opposite perianths on the axis, with male flowers in the axils of the perianths. A male flower consists of a pair of perianths and a sporangiophores carrying 1-8 pollen sacs. A female inflorescence has 4-7 pairs of opposite perianths, with a female flower in the axil of the upper 1-2 perianths, carrying a single ovule. In Welwitschia, male and female inflorescences have many opposite perianths and carry male and female flowers in the axils. A male flower has a pair of basal perianths, a whorl of 6 sporangiophores carrying 3 pollen sacs, and a central nonfunctional ovule. A female flower also has a pair of basal perianths and a single ovule in the perianth. In the male inflorescences of the genus Gnetum, the whorls of the capsules join together to form a ring-shaped sheath in several tiers, with a small number of whorls of male flowers in the axils (some species have a ring of non-functional female flowers at the top). The male flowers are enclosed in a pouch-like perianth and are a single sporangial stipe bearing 2-4 pollen sacs. In the female inflorescences, a single female flower is produced in the axil of the sheath, consisting of a single ovule enclosed in two perianths.

[Michio Tamura]

Flower of angiosperm

It is difficult to directly relate angiosperm flowers to any of the gymnosperm flowers. However, no matter how diverse the angiosperm flowers are, there is a homology between them. Angiosperm flowers, unlike gymnosperm flowers, are originally bisexual compound organs that have female and male organs and a perianth that does not bear ovules or pollen sacs. In other words, the basic shape of angiosperm flowers is a flower receptacle, which is attached from bottom to top to the perianth, stamens, and pistils. Angiosperm flowers are also considered to be a type of shoot, that is, a structure with leaves attached to a stem, and the flower receptacle is considered to be attached to leaf-like organs such as the perianth pieces (or sepals and petals), stamens, and carpels that produce the pistil. The leaf-like organs that produce flowers are called floral organs or flower leaves. Therefore, flowers that retain most of their shoot characteristics are considered primitive.

[Michio Tamura]

Same perianth flower/different perianth flower

Flowers of angiosperms are originally homopertial flowers, with a perianth made up of homogeneous tepals, but in an evolved state the perianth consists of two whorls, an inner and an outer. The outer whorl becomes a calyx that protects the inside when the flower is in bud, and the inner whorl develops into a corolla to attract insects. The calyx is made up of sepals, and the corolla is made up of petals. Flowers with a calyx and corolla like this are called heteropertial flowers. Even in homopertial flowers, the perianth pieces often develop to attract insects, but in some cases they degenerate and become less noticeable, such as in Myricaceae, Juglandaceae, Fagaceae, and Urticaceae. Flowers with this type of perianth are called apetalous flowers. Furthermore, there are also species that do not have perianths, such as Houttuynia cordata, Cranberryaceae, and Trigonaceae, and these are called aperitial flowers. There is a theory that apetalous and aperitial flowers evolved from perianth flowers, and this degeneration is often associated with wind pollination. However, on the other hand, there are also theories that associate these flowers with gymnosperm flowers and consider them to be primitive forms, and there are also theories that consider these flowers to have a different origin from flowers with developed perianths.

[Michio Tamura]

Bisexual and unisexual flowers

Flowers of angiosperms are originally bisexual flowers with both stamens and pistils, but some have unisexual flowers with only one or the other (dioecious flowers). However, unisexual flowers of angiosperms are considered secondary, unlike gymnosperms. In other words, if the pistil of a bisexual flower degenerates, it becomes a male flower, and if the stamen degenerates, it becomes a female flower. Therefore, in the Akebiataceae and Cucurbitaceae families, it is not rare for female flowers to have degenerated stamens, or for male flowers to have degenerated pistils. When female and male flowers are on the same plant, as in Akebia and cucumber, they are called monoecious plants, while when female and male flowers are on different plants, as in hemp, spinach, sorrel, Mulberry, Salicaceae, and Myricaceae, they are called dioecious plants. In addition, in the genera Maple, Fraxinus, and Celastrus, there are often plants with both bisexual and unisexual flowers. This is called mixed habitation.

[Michio Tamura]

Symmetrical surface

Flowers often have several planes of symmetry that pass through the center. When there are two or more planes of symmetry, it is called radial symmetry. When there are two planes of symmetry, as is often seen in the Brassicaceae family, it is sometimes called diradial symmetry. When there is only one plane of symmetry, it is called bilateral symmetry. It is generally believed that the reduction in the number of planes of symmetry in flowers is an evolutionary process. In flowers of genera such as Aconitum and Delphinium, only the perianth is bilaterally symmetrical, but in the Fabaceae, Lamiaceae, Scrophulariaceae, Utricularia, and Orchidaceae, the entire flower is bilaterally symmetrical. When there are no radial planes, it is called asymmetric. Asymmetricity is often associated with the degeneration of the flower structure, as in the case of Cimicifuga genus.

[Michio Tamura]

Number of floral elements

The number of floral elements that make up a flower is generally thought to evolve from indefinite/multiple to fixed/few. However, when the number becomes overwhelming, it may be considered a secondary increase. When the number of floral elements is large, they are often arranged in a spiral, but when the number is small, they are whorled and become a constant number such as three, four, or five. Constant numbering is established throughout the floral elements, from the sepals and petals to the stamens and carpels. Dicotyledonous plants tend to have pentameric flowers, while monocotyledonous plants tend to have trimeric flowers. When whorling and constant numbering are established, the number of stamens becomes two, and then further decreases to one. When there are two stamens, there are two types: those in which the outer whorl is alternate with the petals or corolla lobes, as seen in the Ebaceae and Sapotaceae families, and those in which the outer whorl is opposite them, as seen in the Prunaceae and Ericaceae families. Even when there is only one flower, there are those in which the petals or corolla lobes grow alternately, as in Ericaceae and Salicaceae, and those in which the petals grow opposite each other, as in Primulaceae and Plumageceae.

If we consider floral elements as leaf-like organs, they are originally separate, and fused is an evolved state. There are two types of fusion of floral elements: assortative fusion between floral elements of the same species, and heterospecific fusion between different floral elements. Heterspecific fusion includes the fusion of the corolla and stamens seen in Lamiaceae, and the fusion of the stamens and pistils seen in Cranberryaceae and Orchidaceae. In assortative fusion, the fusion of petals has long been noted, and dicotyledonous plants are often divided into monopetalous and sympetalous flowers. However, monopetalous and sympetalous flowers do not indicate differences in lineage, but are characteristics that indicate the degree of evolution. In addition, whether the carpels are separate or fused is also an important characteristic that indicates the degree of evolution. In a monopetalous flower, there are as many pistils as there are carpels, but in a homopetalous flower, there is only one pistil regardless of the number of carpels, and it is located in the center of the flower, that is, at the apex of the flower bed.

[Michio Tamura]

Inferiorization of ovary

The most important evolutionary event in angiosperm flowers is the inferiorization of the ovary. Because the carpel is the last floral element to form, in primitive flowers the pistil is located above the other floral elements, resulting in an ovary-superior flower. However, with evolution, the receptacle becomes depressed or a calyx tube forms to surround the ovary, and the petals and stamens are at the same height as the ovary, resulting in a mesial (peri-ovary) flower. Furthermore, when the receptacle or calyx tube comes to encase the ovary, the petals and stamens are located above the ovary, resulting in an inferior-ovary flower. The inferiorization of the ovary is for better protection of the ovule, and the receptacle encasing the ovary often participates in the formation of the fruit, becoming a false fruit.

[Michio Tamura]

Pollination method

Gymnosperms are wind-pollinated, meaning that pollen is carried by the wind and attaches to the ovules. On the other hand, there is a strong opinion that angiosperms were originally insect-pollinated, in which pollen is carried to the stigma of other flowers by insects, and that wind-pollinated flowers are a secondary method that arose as flowers degenerated. However, there are also opinions that consider wind pollination to be the original pollination method for angiosperms, and try to relate them to gymnosperms. Bird- and bat-pollinated flowers are modified versions of insect-pollinated flowers, and are particularly common in tropical plants with large flowers. Aquatic plants that bloom underwater are water-pollinated flowers.

[Michio Tamura]

Cultural History of Flowers

The relationship between flowers and people can be learned from direct evidence such as pollen analysis, artefacts, sculptures, paintings and documents, as well as from myths, legends, stories, etymologies and comparisons of plant uses among different ethnic groups.

The oldest known use of flowers in human history dates back to the Paleolithic period 60,000 years ago, when pollen analysis has revealed that flowers such as Centaurea solstitialis , Achillea , Senecio , Muscari and Althaea were offered to Neanderthals buried in the Shanidar Cave in northern Iraq.

In ancient Egypt, water lilies were offered to the gods. A wall painting from Thebes during the New Kingdom shows water lilies in a courtyard pond, the oldest recorded cultivated flower. A wreath of cornflowers was found in Tutankhamun's tomb, and other flowers such as corn poppies and safflowers were left in the tombs of ancient Egyptian kings. Interest in exotic flowers dates back to ancient times, and around 1450 BC, Thutmose III carved 275 plants, including local pomegranates and Araceae, into the temple at Karnak to commemorate his Syrian expedition. Among Tutankhamun's grave goods was an ointment spoon shaped like a pomegranate, which can be said to be one of the oldest and greatest works of art that depicts plants in terms of its realistic accuracy. The Minoan civilization of Crete has wall paintings of Madonna lilies and vases painted with saffron.

Flowers such as calendula, daffodil, anemone, and violet appear in Greek mythology. The ancient Greeks used flower crowns and wreaths in their ceremonies. They were made from Madonna lilies, daffodils, sweet violets, anemones, thymes, marjoram, and myrtle, and were cultivated (Theophrastus, De materia medica (3rd century BC) and others). Dioscorides' De materia medica (1st century) describes the cultivation of the succulent Aeonium arborēum .

Flowers are also closely related to religion. Although no flowers are mentioned in the Bible as decorations, Madonna lilies were often depicted in medieval religious paintings as the flower of the Virgin Mary. In India, the lotus appears in Hindu mythology, and is also a sacred flower in Buddhism. Many other flowers also appear in Buddhist scriptures, including ashoka, deico, goldenrod, pomegranate, jasmine, and oleander.

Chinese flowers include peonies, lotus flowers, and orchids in the Book of Songs from the Zhou dynasty, and chrysanthemums and orchids in the Book of Rites (1st century BCE), but they were used more for medicinal purposes than for decorative purposes. Floriculture developed during the Tang dynasty, and Yao likened 30 kinds of flowers to guests in his Xixi Conghua. They include the peony (noble guest), plum (wine guest), orchid (ghost guest), peach (mysterious guest), apricot (beautiful guest), lotus (river guest), osmanthus (rock guest), begonia (Shu guest), azalea (mountain guest), pear (light guest), chrysanthemum (longevity guest), hibiscus (drunkard guest), wintersweet (winter guest), clove (lilac, passionate guest), rose (rose, assassin guest), hibiscus (seasonal guest), and pomegranate (village guest), and most of them are flowering trees.

In Japan, about 80 species are found in each of the Kojiki and Nihon Shoki, totaling about 100 species of plants, but only about one-eighth of them have beautiful flowers or fruit: lilies, cherry blossoms, camellias, pears, wisteria, Chinese lantern plant, ground cherry, lotus, the foreign plant Tachibana, plum, Japanese plum, and Japanese eupatorium. However, in the Manyoshu, of the 160 or so plants mentioned, the number of herbs with beautiful flowers increases to 44. At the time, flowering trees were overwhelmingly more common than herbaceous flowers cultivated at home. Native flowering trees in Japan include the Japanese laurel, the andromeda, the bush clover, the camellia, the wisteria, the cherry blossom, the pear, the deutzias, the hydrangea, the China chinaberry, the silk tree, and the azalea. Flowering plants include the dianthus, the lily, and the lotus. Introduced flowering trees include the plum, the peach, the Japanese plum, the Japanese laurel, and the tachibana. Flowering plants include the karaai (cockscomb) and the kurenai (safflower). In addition, pines, bamboos, maples, and Chinese weeping willows and trifoliate oranges were also cultivated. Deutzias were used as hedges, which was an early example of this in the world. In the Manyoshu, there are no flowers used for indoor decorations, except for the lily kazura (4086, 4087). In the Man'yoshu, there is a poem that says, "I am reluctant to let the white dew fall, so I pick only the autumn bush clover and leave it to wither" (2099). At that time, even if flowers were picked by hand, they were simply looked at or displayed as headpieces or moss, and it seems that there was no custom of arranging flowers indoors. The oldest record of ikebana is an offering to Buddha, found in the Todaiji Yoroku on April 10, 752 (Tenpyo Shoho 4), which states, "We offer flowers to the Buddha Vairocana, who has purified the eastern mountains and called Nii-nii." Ikebana hardly appears in Heian literature, including The Pillow Book and The Tale of Genji, except for a few cherry blossoms and gentians. It became popular after the Muromachi period.

Japanese floriculture developed rapidly during the Edo period, as evidenced by works such as "Kadan Komoku" (1681) by Mizuno Motokatsu (date of birth and death unknown), "Kafu" (1694) by Kaibara Ekiken, and the "Kadan Chikinsho" (1695) and other works by successive generations of Ito Ihei. Following Anrakuan Sakuden's Hyakuchinshu (1630), Ito Ihei Sannojo's Kinshumakura (1692) of azaleas, and Yamamura Yuen's Shiyou Marchuki (1691), illustrated books of maples, chrysanthemums, cherry blossoms, morning glories, plum blossoms, lotus flowers, and Japanese irises were published one after another. In addition, breeding of flowers native to Japan, such as primroses, dianthus, Japanese quail, anemone, ambrosia, Dendrobium, Japanese laurel, Japanese laurel, tricolor, pine orchid, and Japanese laurel, became popular. The fact that common people also participated in these activities makes it a flower culture that was rare in the world at the time. In particular, they were pioneers in the world in the appreciation of variegated and ornamental plants, and these were collected in works such as Shigetei Kinta's (1793-1862) "Somoku Kihinka Kagami" (1827) and Mizuno Tadatoshi's (1767-1834) "Somoku Nishikiyoshu" (1829).

Japanese botanical arts, including flower ikebana, bonsai, hedges, and landscaping, have continued to develop since the Meiji period, and in modern times have been expanded to include the field of flower design, forming Japan's floral culture.

[Hiroshi Yuasa]

Folklore

Interest in the color, fragrance, and shape of flowers is common to all human beings, and is reflected in various customs. They are used in myths and legends, religious ceremonies, annual events, gift-giving, the meaning of flowers, national flowers, fortune telling, and more. In Japan, up until the time of the Manyoshu, the word "flower" often meant plum blossoms, but by the time of the Kokinshu, cherry blossoms had become more popular. Colorful flowers often seem to be associated with Buddhism. Popular flowers change depending on the ethnic group and the era.

Let's take a look at some scenes in which flowers appear, focusing on annual events. First, in some regions, the welcoming of New Year's Kadomatsu (ceremonial pine decorations) is called Hanamukae (flower welcoming), even though it is not a flower. The kezuribana (decorative sculpted flowers) of Koshogatsu (lit. Little New Year) are tethered to tree branches as a form of incantation to celebrate a good harvest, but in some regions, they are called Hanakazari (flower decorations), Hanashogatsu (flower decorations), and Hanakaki-sekku (flower-kaki festival), and in some regions, the period from Koshogatsu to the end of the month is called Hana no Uchi (flower season). Cherry blossom viewing around March of the lunar calendar is widely held, and since spring farm work begins around that time, the blooming of certain flowers is used as a guide for when to start each task. The Buddha's Day celebration on April 8 of the lunar calendar (now mostly the solar calendar) is also called the Flower Festival, and is known for covering the roof of a temple with flowers, but there is also the custom of Takahana (tall flowers) and Tendou-bana (flowers with flowers) in which flowers are attached to the end of a long pole and hung on the same day. During the Bon Festival, there is a festival of flowers such as ominaeshi (a type of Japanese laurel), and the Bon Festival market where these flowers are sold is also called a flower market. The seven herbs of spring are mainly wild plants, but the seven herbs of autumn are also made up of wild flowers. Some coats of arms feature flowers, and the imperial family uses chrysanthemums. Flower arranging has a background in Buddhism and has elevated the Japanese sense of aesthetics to an art form.

[Shoji Inoguchi]

literature

A general term for flowers of plants and trees, or a term that conceptualizes flowers as typical scenery of natural beauty, such as flowers, birds, wind, moon, snow, moon, flowers, birds, flowers, and autumn leaves. In addition, the Yakumo Gosho (13th century) states that "in modern times, all flowers that are simply called flowers are cherry blossoms," and later it came to be used specifically to refer to typical flowers such as cherry blossoms. As the Manyoshu states, "The city of Nara, with its green blossoms, is now in full bloom, like the fragrance of blooming flowers" (Volume 3, Oono no Oyu), flowers are scenery that symbolize splendor, and many words that express gaiety, such as "hana yaku," "hana meku," "hana banashi," and "hana yaka," are related to "flowers." In addition, as in the Konohana no Sakuya-hime in the Kojiki, it can also be described as beautiful but fleeting, as in the Kana preface of the Kokinshu, "Because the world today is colorful, and people's hearts have become flowers," and as in the Tale of Genji, "The Lady of the Flowers" "Because the Princess (Niou no Miya) is in the flower's heart," it can also express infidelity. In poetry theory, "flower" and "fruit" are used in contrast to each other, and in this case, too, they are sometimes used with a sense of vanity, as well as the meaning of "words" in contrast to "heart," or the expression of feelings. In Zeami's theory of Noh, "flower" is also an important aesthetic concept, and in works such as "Fushikaden," it is used as a term to mean the inner charm, or gaiety, that is expressed according to the actor's age and ability, and this has been passed down to Kabuki and other forms of theater. Flowers that are frequently mentioned in the "Manyoshu" include morning glories (bellflowers), ashibi, irises, unobtrusive flowers, plum blossoms, iris, kudzu, safflower, cherry blossoms, pampas grass, violets, tachibana, moonflower, azalea, camellia, dianthus, bush clover, wisteria, shisakura, peach, Japanese yarrow, lilies, forget-me-nots, and lady's mantle. The "Kokinshu" adds new flowers such as the "chrysanthemum." In the section "Flowers of the trees" in "The Pillow Book," mentions "red plum, cherry blossom, wisteria, tangerine, pear, paulownia, and elm," while in the section "Flowers of the grass" mentions "carnations, lady's mantles, bellflowers, morning glories, cut hawthorn, chrysanthemums, vase violets, gentian, Japanese laurel flowers, crab-hi (gooseberry) flowers, bush clover, double-flowered Japanese bush clover, evening primrose, Japanese laurel flowers, reed flowers, and pears." Though some are unusual, it is safe to say that this book covers almost all the flowers found in court literature. The "Hundred Flowers" section of "Fuzoku Monzen" (Selection of Manners and Literature) (published in 1706) discusses flowers such as "plum, red plum, cherry, begonia, pear, camellia, peach, wisteria, yellow laurel, rose, peony, Chinese peony, poppy, iris, lily, lily of the valley, snowbell, dayglory, hydrangea, unosmanthus, morning glory, cockscomb, orchid, balsam, lady's mantle, bellflower, bush clover, chrysanthemum, winter chrysanthemum, and winter peony" as if they were women, and lists representative varieties of flowers in early modern literature. Flowers have always occupied a prominent place as a subject in Japanese literature, particularly in poetry from waka to haiku, and expressing the feelings of waiting for flowers to bloom and regretting their withering has been a central theme in literature depicting the beauty of nature.

[Teruhiko Komachiya]

"Plant Morphology" by Hama Takeo (1958, Corona Publishing) ▽ "System of Angiosperms" by Tamura Michio (1974, Sanseido) ▽ "Living Ancient Plants" by Tamura Michio (1974, Hoikusha) ▽ "Flower Bed Earthenware Selections and Supplementary Earthenware Selections" by Ito Ihei Sannojo and Ito Ihei Masatake (1983, Yasaka Shobo) ▽ "Modern Biology Series: Higher Plants A2" edited by Honda Shoji and edited by Yamazaki Kei (1984, Nakayama Shoten)" ▽ "My Flower Museum" by Tsukamoto Yotaro (1985, Asahi Shimbun, Asahi Sensho) ▽ "Introduction to Plant Observation - Flowers, Stems, Leaves, and Roots" by Hara Masashi, Fukuda Taiji, and Nishino Eimasa (1986, Baifukan) ▽ "Pliny's Natural History" translated by Sadao Nakano et al. (1986, Yuzankaku Publishing) " ▽ "Cultural History of Flowers - People Who Created the History of Flowers" by Yukio Haruyama (2012, Japan Library Center)" ▽ "Flower Resume" by Hiroshi Yuasa (Kodansha Academic Library)

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

Japanese:

シダ植物の花

ツクシはスギナの花で、胞子嚢をつける胞子嚢托(たく)が輪生し、それが数輪、穂状に集まったものである。また、クラマゴケでは、上面の基部に胞子嚢をつけた小葉が集まって穂をつくるが、胞子嚢は雌性の大胞子嚢と雄性の小胞子嚢とに分化し、それらをつける小葉は一つの穂に混じってつく。

［田村道夫］

裸子植物の花

裸子植物では、雌性の大胞子嚢は珠皮に包まれて胚珠(はいしゅ)となり、雄性の小胞子嚢は花粉嚢となる。

［田村道夫］

ソテツ綱・イチョウ綱

ソテツ綱では、花粉嚢は小胞子葉の上面に3～4個ずつ集まって全面につき、胚珠は大胞子葉の下部の縁(へり)につく。小胞子葉は穂状に密集して雄花となり、大胞子葉は茎頂に緩く集まって雌花をつくる。イチョウ綱では、花粉嚢は2個ずつ小胞子嚢托につき、それが穂状に集まって雄花となる。胚珠は2個が対(つい)になって大胞子嚢托につくが、それの上端部は広がって椀(わん)状となり、胚珠の基部を取り囲む。この椀状部は、まれに伸び広がって葉状になることがある（これを「お葉付きイチョウ」とよぶ）。このことから、椀状部は退化した大胞子葉と解釈されることもある。

［田村道夫］

球果綱

球果綱（マツ綱）では、普通、いくつかの花粉嚢が鱗片(りんぺん)の下面につき、それが軸に穂状に集まって雄花となる。球果綱を通じて、雄花の基本構造はほぼ一様とみなすことができるが、雌花はきわめて多様である。多くは鱗片の上面に胚珠をつけるが、これが軸に穂状に集まってつき、球花をつくる。スギ科などでは、胚珠をつけている鱗片は単純であるが、マツ科などでは、その下にもう1枚の鱗片があって二重構造となっている。進化のうえからみると、球果は、本来はもっと複雑な構造をもっていたもので、古生代石炭紀に栄えたコルダイテスでは、球花の軸に包（包葉）がつき、それの腋(えき)より伸びた枝に葉と胚珠がついていた。やがて、包より腋生する枝が退化し、全体が穂としてのまとまりが強くなる方向に進化していったとみなされている。したがって、現生の植物でも、マツのように球花の鱗片が二重になっているものは原始的で、下の鱗片は包、胚珠をつける上の鱗片は退化した枝またはそれに属するものと考えられる。そして、スギのように一重のものは、その2枚が合着したものとみなされる。球花をつくる鱗片の数は、さらに減少する方向に進化し、イヌマキ科では胚珠をつける鱗片1枚で1個の球花をつくるに至っている。

［田村道夫］

グネツム綱

グネツム綱では、雄花も雌花も若いときは、膜質の花被(かひ)に包まれる。マオウ属の雄花穂では、軸に2～8対の包が対生し、包の腋に雄花をつける。雄花は1対の花被と、それに覆われた1～8個の花粉嚢をつける小胞子嚢托よりなる。雌花穂には4～7対の対生する包があり、雌花は上部の1～2枚の包の腋につき、花被に包まれた1個の胚珠である。ウェルウィッチア属の雄花穂と雌花穂では、多数の包を対生し、その腋にそれぞれ雄花と雌花をつける。雄花は基部に1対の小包をもち、花被の中に3個の花粉嚢をつける小胞子嚢托を6本輪生し、中央には機能のない胚珠がある。雌花も基部に1対の小包があり、花被に包まれた1個の胚珠よりなる。グネツム属の雄花穂では、輪生した包が合着して数段の輪状の鞘(しょう)をつくり、その腋に輪生する雄花を少数輪つける（いちばん上に機能のない雌花の輪をつける種もある）。雄花は袋状の花被に包まれ、2～4個の花粉嚢をつける1本の小胞子嚢托である。雌花穂では、鞘の腋に1輪の雌花を生じ、雌花は2枚の花被に包まれた1個の胚珠よりなる。

［田村道夫］

被子植物の花

被子植物の花を裸子植物の花のいずれかと直接的に関係づけることは困難である。しかし、被子植物の花は、いかに多様であっても、それらの間に相同性を認めることができる。被子植物の花は裸子植物の花と違って、本来、雌性器官と雄性器官をもち、それに胚珠や花粉嚢をつけない花被をもった両性の複合器官である。すなわち、被子植物の花は、花床(かしょう)に下から上へと花被、雄蕊(ゆうずい)群、雌蕊(しずい)群をつけたのが基本的な形である。また、被子植物の花は一種のシュート（苗条）、すなわち、茎に葉のついた構造と考えられ、花床という茎的器官に、花被片（または萼片(がくへん)と花弁）、雄蕊（雄しべ）、および雌蕊（雌しべ）をつくっている心皮(しんぴ)といった葉的器官がついたものとみなされる。花をつくっている葉的器官を花器官または花葉(かよう)という。したがって、シュートとしての性質をよく保っている花は原始的なものとみなされるわけである。

［田村道夫］

同花被花・異花被花

被子植物の花は、本来、同質の花被片よりなる花被をもつ同花被花であるが、進化した状態では花被は内外2輪よりなる。外輪はつぼみのとき内部を保護する萼となり、内輪は昆虫誘引のために発達して花冠となる。萼は萼片よりなり、花冠は花弁よりなる。このように、萼と花冠をもった花を異花被花という。同花被花でも花被片は昆虫誘引のために発達することが多いが、ヤマモモ科、クルミ科、ブナ科、イラクサ科などのように、退化して目だたなくなる場合もある。このような花被をもつ花は無花弁花とよばれる。さらに、ドクダミ科、センリョウ科、ヤマグルマ科などのように花被をもたないものもあり、これは無花被花とよばれる。無花弁花や無花被花は、同花被花から退化によって生じたとする説があり、この退化は風媒(ふうばい)と関係づけられることが多い。しかし、一方では、これらの花を裸子植物の花と関係づけ、原始的な形態とみなす説もあるし、これらの花と発達した花被をもつ花とは、起源を異にすると考える説も出されている。

［田村道夫］

両性花・単性花

被子植物の花は、本来、雄蕊と雌蕊とをもつ両性花であるが、なかには、どちらか一方しかもたない単性花（雌雄異花）もある。しかし、被子植物の単性花は裸子植物の場合とは異なって二次的なものといえる。すなわち、両性花から雌蕊が退化すれば雄花、雄蕊が退化すれば雌花となる。したがって、アケビ科、ウリ科などでは、雌花に退化した雄蕊があったり、雄花に退化した雌蕊のある場合が少なくない。アケビ、キュウリなどのように雌花と雄花が一つの個体につく場合を雌雄同株、アサ、ホウレンソウ、スイバ、クワ科、ヤナギ科、ヤマモモ科などのように雌花と雄花が別な個体につく場合を雌雄異株という。また、カエデ属、トネリコ属、シュロソウ属などでは、しばしば両性花と単性花とをもつものがみられる。これを雑居性という。

［田村道夫］

相称面

花には、多くの場合、中心を通ったいくつかの相称面がある。二つ以上の相称面をもつ場合を放射相称という。アブラナ科にしばしばみられるような二つの相称面をもつ場合を二放射相称とよぶこともある。相称面が一つの場合を左右相称という。一般に花の相称面が減少することは進化と考えられている。トリカブト属、ヒエンソウ属などの花では花被だけの左右相称であるが、マメ科、シソ科、ゴマノハグサ科、タヌキモ科、ラン科などでは花全体が左右相称となる。また、放射面をもたない場合を不相称という。不相称は、サラシナショウマ属の例にみるように、花の構成の退化と関連することが多い。

［田村道夫］

花要素の数

花を構成している花要素の数は一般に不定・多数から一定・少数へと進化すると考えられる。しかし、おびただしい数になる場合は、二次的な増数とみなされることもある。花要素の数が多ければ螺旋(らせん)に配列することが多いが、少なくなれば輪生し、かつ、3数、4数、5数などに定数化するようになる。定数化は萼片、花弁から雄蕊、心皮に及び、花要素全体を通じて確立する。双子葉植物では5数性の花が多く、単子葉植物には3数性の花が多い。輪生と定数化が確立した場合、雄蕊は2輪になり、さらに減輪して1輪になる。雄蕊が2輪である場合には、カキ科、アカテツ科などにみられるように、外輪が花弁または花冠裂片と互生するものと、イチヤクソウ科、ツツジ科などにみられるように外輪がそれらと対生するものとがある。また、1輪である場合にも、ツツジ科やイワウメ科などにみられるように、花弁や花冠裂片と互生するものと、サクラソウ科やイソマツ科にみられるように、それらと対生するものとがある。

　花要素を葉的器官であると考えると、離生しているのが本来であり、合着しているのは進化した状態といえる。花要素の合着には、同じ種類の花要素間の同類合着と、異なった花要素間の異類合着とがある。異類合着には、シソ科などにみられる花冠と雄蕊の合着や、センリョウ科、ラン科などにみられる雄蕊と雌蕊との合着などがある。同類合着では花弁の合着が古くから注目され、双子葉植物はしばしば離弁花類と合弁花類に二分される。しかし、離弁花と合弁花は系統の違いを示すのではなく、進化の程度を示す特徴である。また、心皮が離生しているか合着しているかも進化の程度を示す重要な特徴である。離生心皮花では心皮の数だけの雌蕊があるが、合生心皮花では心皮の数にかかわらず雌蕊は1個で、花の中央、すなわち花床の頂端に位置する。

［田村道夫］

子房の下位化

被子植物の花におけるもっとも重要な進化として、子房の下位化がある。心皮はいちばんあとに形成される花要素であるため、原始的な花では、雌蕊は他の花要素の上に位置して子房上位花となる。しかし、進化に伴って、花床がへこんだり萼筒が形成されて子房を取り巻き、花弁や雄蕊が子房と同じくらいの高さにつくと子房中位（周位）花となる。さらに、花床や萼筒が子房を包むようになると、花弁や雄蕊のつく位置は子房より上になり、子房下位花となる。子房の下位化は胚珠の保護の強化のためであり、しばしば子房を包んだ花床が果実の形成に参加して偽果(ぎか)となる。

［田村道夫］

送粉法

裸子植物では、花粉は風によって運ばれて胚珠につく風媒花である。一方、被子植物では、花粉が昆虫によって他の花の柱頭に運ばれる虫媒花が本来であり、風媒花は花の退化に伴って由来した二次的なものとみなすという意見が強い。しかし、被子植物でも風媒を本来の送粉法であるとして、裸子植物と関係づけようとする意見もある。鳥媒花やこうもり媒花は虫媒花の変形で、とくに大形の花をつける熱帯性植物によくみられる。水中で開花する水草は水媒花である。

［田村道夫］

花の文化史

花と人のかかわりは、花粉分析、遺物、彫刻、絵画、文献などの直接的証拠のほか、神話、伝説、物語、語源、民族間の植物利用の比較などから知ることができる。

　人類最古の花利用は、6万年前の旧石器時代にさかのぼり、イラク北部のシャニダールの洞窟(どうくつ)に埋葬されたネアンデルタール人に、ヤグルマギクの1種Centaurea solstitialis、ノコギリソウ属Achillea、セネシオ（キオン）属Senecio、ムスカリ属Muscari、タチアオイ属Althaeaなどの花が手向けられていたことが、花粉分析から明らかにされている。

　古代のエジプトではスイレンが神へ献花された。新王国時代のテーベの壁画には中庭の池のスイレンが描かれるが、これは記録に残る最古の栽培花である。ツタンカーメンの墓からはヤグルマギクの花輪が発見され、ほかにもヒナゲシやベニバナなどが古代のエジプト王の墓に残されていた。異国の花への関心は古く、トゥトメス3世は紀元前1450年ごろシリア遠征の記念に、その地のザクロやサトイモ科をはじめ275もの植物をカルナックの神殿に刻んだ。ツタンカーメンの副葬品にザクロをかたどった香膏(こうこう)用スプーンがあり、写実の正確さにおいて植物を意匠する最古最高の芸術品の一つといえよう。クレタのミノア文明にはマドンナリリーの壁画やサフランを描いた壺(つぼ)がある。

　ギリシア神話にはキンセンカ、スイセン、アネモネ、スミレなどの花々が登場する。古代のギリシア人は花冠や花輪を儀式に使った。それらはマドンナリリー、スイセン、ニオイスミレ、アネモネ、イブキジャコウソウの類、マヨナラ、ギンバイカなどでつくられ、栽培下にあった（テオフラストス『植物の探究』（前3世紀）ほか）。ディオスコリデスの『薬物誌』De materia medica（1世紀）には、多肉植物のアエオニウムの1種Aeonium arborēumの栽培が記述されている。

　花は宗教とも関係が深い。聖書に飾られた花は出てこないが、マドンナリリーは聖母マリアの花として、中世の宗教絵画には数多く描かれた。インドではヒンドゥーの神話にハスが登場し、仏教でもハスは聖花である。ほかにも仏典にはアショカ、デイコ、キンコウボク、ザクロ、マツリカ、キョウチクトウをはじめ多数の花が顔を出す。

　中国の花は周代の『詩経』にシャクヤク、ハス、ランが、『礼記(らいき)』（前1世紀）にキクやランが載るが、花を観賞するよりは薬用としての面が強かった。唐代に至って花卉(かき)園芸は発達を遂げ、姚(よう)氏は『西渓叢話(そうわ)』で花卉30種を客に例えてあげた。それらは牡丹(ぼたん)（貴客）、梅（酒客）、蘭(らん)（幽客）、桃（妖(よう)客）、杏(あんず)（艶(えん)客）、蓮(はす)（渓客）、木犀(もくせい)（岩客）、海棠(かいどう)（蜀(しょく)客）、躑躅(つつじ)（山客）、梨(なし)（淡客）、菊（寿客）、木芙蓉(きふよう)（酔客）、蝋梅(ろうばい)（寒客）、丁香（ライラック、情客）、玫瑰(まいかい)（バラ、刺客）、木槿(むくげ)（時客）、安石榴(ざくろ)（村客）などで、ほとんどが花木である。

　日本では『古事記』『日本書紀』にそれぞれ約80種、あわせておよそ100種の植物がみられるが、そのなかで花や実の美しい植物は、ユリ、サクラ、ツバキ、ナシ、フジ、ヒオウギ、ホオズキ、ハス、外来のタチバナ、スモモ、ニワウメ、フジバカマと8分の1ほどにすぎない。ところが『万葉集』では、名のあがる160余りの植物のうち、花の美しい草木は44種に増える。当時、人家で栽培されていた花は草花より花木が圧倒的に多かった。日本自生の花木にはヤマブキ、アセビ、ハギ、ツバキ、フジ、サクラ、ナシ、ウツギ、アジサイ、センダン、ネムノキ、ツツジ、草花にはナデシコ、ユリ、ハス、渡来種の花木としてウメ、モモ、スモモ、ニワウメ、タチバナ、草花にカラアイ（ケイトウ）、クレナイ（ベニバナ）があり、ほかにマツ、タケ、カエデ、中国産のシダレヤナギやカラタチなども栽培されていた。ウツギは生け垣として使われているが、これは世界的にみて早い。『万葉集』には、室内で飾られた花はユリの蘰(かずら)（4086、4087）を除いてない。『万葉集』には「白露の置かまく惜しみ秋萩(はぎ)を折りのみ折りて置きや枯らさむ」（2099）と詠まれているように、当時は花を手折っても、そのまま眺めるか挿頭華(かざし)や蘰にして飾り、室内で花をいける習慣はなかったとみられる。いけ花のもっとも古い記録は仏への供華(くげ)で、『東大寺要録』に載る752年（天平勝宝4）4月10日、元興(がんごう)寺から送られた「東の山辺をきよみ邇井々(にいい)せる盧舎那(るしゃな)仏に花たてまつる」の記述である。いけ花は、『枕草子(まくらのそうし)』『源氏物語』をはじめとする平安文学には、サクラ、リンドウなど少数を除いて、ほとんど登場しない。盛んになるのは室町時代以降である。

　日本の花卉園芸は江戸時代に入って急速な発展を遂げた。それらは水野元勝(もとかつ)（生没年不詳）の『花壇綱目』（1681）、貝原益軒の『花譜』（1694）および代々の伊藤伊兵衛による『花壇地錦抄(ちきんしょう)』（1695）をはじめとする一連の地錦抄シリーズに跡をとどめる。種類別には安楽庵策伝(あんらくあんさくでん)の『百椿(ひゃくちん)集』（1630）、伊藤伊兵衛三之丞(さんのじょう)（？―1719）のツツジ類の『錦繍枕(きんしゅうまくら)』（1692）、山村遊園のボタンの『紫陽(しよう)三月記』（1691）以降、カエデ、キク、サクラ、アサガオ、ウメ、ハス、ハナショウブなどの図集が次々と刊行された。さらにサクラソウ、ナデシコ、ミヤマウズラ、ミスミソウ、フクジュソウ、セッコク、マンリョウやカラタチバナ、マツバラン、オモトなど日本固有の草花を中心とする品種改良が流行した。それらは庶民も加わった点で、当時世界に類の少ない花文化であったといえよう。なかでも斑(ふ)入りや観葉植物の観賞も世界に先駆け、繁亭金太(はんていきんた)（1793―1862）の『草木奇品家雅見(かがみ)』（1827）や水野忠暁(ただとし)（1767―1834）の『草木錦葉集』（1829）に集大成された。

　いけ花、盆栽、生け垣、造園など日本の植物芸術は明治以降も発展し、現代はそれにフラワー・デザインの分野も加わり、日本の花文化を形成している。

［湯浅浩史］

民俗

花の色、香、形に対する関心は人類に共通のもので、さまざまな習俗に投影している。神話・伝説をはじめ、信仰儀礼、年中行事、贈答、花言葉、国花、占いなどに用いられる。日本では『万葉集』のころまでは、単に花といえば梅の花をさす例が多く、『古今集』の時代になると桜が勢力を増してくる。色鮮やかな花は仏教に結び付いている場合が多いように見受けられる。民族によっても、時代によっても、人気のある花は変化するものである。

　年中行事を中心に、花の登場する場面を拾い上げてみる。まず、花ではないが正月用の門松迎えを花迎えとよぶ地方がある。小正月(こしょうがつ)の削り花は、木の枝につけて豊作を予祝する呪術(じゅじゅつ)であるが、花飾り、花正月、花かき節供などといい、小正月から月末までを花の内とよぶ地方もある。旧暦3月ごろの花見は広く行われており、そのころから春の農作業にとりかかるので、特定の花の咲きぐあいによって、各作業を始める時期の目安にしている。旧暦（現在では多くは太陽暦）4月8日の灌仏会(かんぶつえ)は花祭ともいい、御堂(みどう)の屋根を花で葺(ふ)くことが知られているが、ほかにも同日に長い竿(さお)の先に花をつけて掲げる高花(たかはな)・天道花(てんとうばな)の習俗がある。盆にはオミナエシなどの盆花迎えがあって、その花を売る盆市(いち)を花市ともいう。春の七草は野草が中心であるが、秋の七草は野花でまとめている。紋章にも花をあしらったものがあり、皇室は菊の花を用いている。華道は仏教を背景として、日本人の美意識を芸道に高めた。

［井之口章次］

文学

草木の花の総称、あるいは花鳥風月、雪月花、花鳥、花月、花紅葉(はなもみじ)など自然美の代表的な景物としての花を概念化した呼称。また、『八雲御抄(やくもみしょう)』（13世紀）に「近代はただ花と云(い)ふは皆桜也(なり)」というように、のちには桜など典型的な花を限定していうようにもなった。『万葉集』に「青丹(あをに)よし奈良の都は咲く花のにほふがごとく今盛りなり」（巻3・小野老(おゆ)）とあるように華やかさを象徴する景物であり、「はなやぐ」「はなめく」「はなばなし」「はなやか」など、華美を表現する語にも「花」に関連するものが多い。また、『古事記』上の木花開耶姫(このはなのさくやひめ)のように、美しいがはかないものともされて、さらに、『古今集』「仮名序」の「今の世の中色に付き、人の心花になりにけるにより」のように軽薄さ、『源氏物語』「宿木(やどりぎ)」の「花心におはする宮（匂宮(におうのみや)）なれば」のように不実などを表すこともある。歌論で「花」「実」を対照させて用いるが、この場合も、「心」に対する「詞(ことば)」、心情に対する表現の意とともに、虚飾的な語感で用いられることもある。世阿弥(ぜあみ)の能楽論でも、「花」は重要な美的理念であり、『風姿花伝』などで、役者の年齢や力量に応じて表される内面的な魅力、いわば華やぎを意味する術語として用いられており、それは歌舞伎(かぶき)などにも継承されていく。『万葉集』の花としては、「朝顔（桔梗(ききょう)か）・馬酔木(あしび)・菖蒲(あやめ)・卯(う)の花・梅・杜若(かきつばた)・葛(くず)・紅花・桜・薄(すすき)・菫(すみれ)・橘(たちばな)・月草(つきくさ)・躑躅(つつじ)・椿(つばき)・撫子(なでしこ)・萩(はぎ)・藤・紫草・桃・山吹・百合(ゆり)・忘れ草（萱草(かんぞう)）・女郎花(をみなへし)」などが多く詠まれ、『古今集』では新たに「菊」などが加わっている。『枕草子(まくらのそうし)』の「木の花は」の段には、「紅梅・桜・藤・橘・梨(なし)・桐(きり)・楝(あふち)」、「草の花は」の段には、「撫子・女郎花・桔梗・朝顔・刈萱(かるかや)・菊・壺(つぼ)菫・竜胆(りんだう)・かまつかの花・かにひ（雁緋）の花・萩・八重山吹・夕顔・しもつけの花・葦(あし)の花・薄」などが取り上げられており、特異なものもあるが、王朝文学にみられる花はここにほぼ網羅されていると考えてよいだろう。『風俗文選(ふうぞくもんぜん)』（1706年刊）の「百花譜」は、「梅・紅梅・桜・海棠(かいだう)・梨・椿・桃・藤・山吹・薔薇(しゃうび)・牡丹(ぼたん)・芍薬(しゃくやく)・罌粟(けし)・杜若・百合・姫百合・合歓(ねむ)・昼顔・紫陽花(あぢさゐ)・卯の花・朝顔・鶏頭(けいとう)・蘭(らん)・鳳仙花(ほうせんくわ)・女郎花・桔梗・萩・菊・寒菊・冬牡丹」などの花を女性に見立てて論じたもので、近世の文学における花の代表的な品種が掲げられている。和歌から俳句に至る詩歌を中心に、日本の文学においてつねに花が題材としてもっとも大きな位置を占めており、花が咲くのを待ち、花が散るのを惜しむ心情を表出することが、自然美を描く文学の中心的な主題であった。

［小町谷照彦］

『浜健夫著『植物形態学』（1958・コロナ社）』▽『田村道夫著『被子植物の系統』（1974・三省堂）』▽『田村道夫著『生きている古代植物』（1974・保育社）』▽『伊藤伊兵衛三之丞・伊藤伊兵衛政武著『花壇地錦抄・増補地錦抄』（1983・八坂書房）』▽『本田正次監修、山崎敬編『現代生物学大系　高等植物A2』（1984・中山書店）』▽『塚本洋太郎著『私の花美術館』（1985・朝日新聞社・朝日選書）』▽『原襄・福田泰二・西野栄正著『植物観察入門――花・茎・葉・根』（1986・培風館）』▽『中野定雄他訳『プリニウスの博物誌』（1986・雄山閣出版）』▽『春山行夫著『花の文化史――花の歴史をつくった人々』（2012・日本図書センター）』▽『湯浅浩史著『花の履歴書』（講談社学術文庫）』