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Didymelaceae
''Didymeles'' is a genus of flowering plants. It is variously treated as the only genus of the family Didymelaceae — or in the family Buxaceae, as in the APG IV system. The genus ''Didymeles'' is restricted to Madagascar and the Comoros. In Madagascar, the two species are found in humid montane habitats, up to 1,500 m, in two disconnected areas in the north-east and south-east of the island. Fossils assignable to this genus have been found in New Zealand, suggesting a much wider distribution in the past. The conservation status of ''D. integrifolia'' has been assessed as of "least concern". Description Species are dioecious (i.e. "male" and "female" flowers occur on separate plants). Individual flowers have a very simple structure, without obvious petals or sepals. Female flowers have been interpreted in different ways, either as having two carpels or as occurring close together in pairs, each with a single carpel. ''Didymeles'' species are evergreen trees. The simp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Didymeles Integrifolia
''Didymeles'' is a genus of flowering plants. It is variously treated as the only genus of the family Didymelaceae — or in the family Buxaceae, as in the APG IV system. The genus ''Didymeles'' is restricted to Madagascar and the Comoros. In Madagascar, the two species are found in humid montane habitats, up to 1,500 m, in two disconnected areas in the north-east and south-east of the island. Fossils assignable to this genus have been found in New Zealand, suggesting a much wider distribution in the past. The conservation status of ''D. integrifolia'' has been assessed as of "least concern". Description Species are dioecious (i.e. "male" and "female" flowers occur on separate plants). Individual flowers have a very simple structure, without obvious petals or sepals. Female flowers have been interpreted in different ways, either as having two carpels or as occurring close together in pairs, each with a single carpel. ''Didymeles'' species are evergreen trees. The s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Didymeles Madagascarensis
''Didymeles'' is a genus of flowering plants. It is variously treated as the only genus of the family Didymelaceae — or in the family Buxaceae, as in the APG IV system. The genus ''Didymeles'' is restricted to Madagascar and the Comoros. In Madagascar, the two species are found in humid montane habitats, up to 1,500 m, in two disconnected areas in the north-east and south-east of the island. Fossils assignable to this genus have been found in New Zealand, suggesting a much wider distribution in the past. The conservation status of ''D. integrifolia'' has been assessed as of "least concern". Description Species are dioecious (i.e. "male" and "female" flowers occur on separate plants). Individual flowers have a very simple structure, without obvious petals or sepals. Female flowers have been interpreted in different ways, either as having two carpels or as occurring close together in pairs, each with a single carpel. ''Didymeles'' species are evergreen trees. The s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Didymeles Perrieri
''Didymeles'' is a genus of flowering plants. It is variously treated as the only genus of the family Didymelaceae — or in the family Buxaceae, as in the APG IV system. The genus ''Didymeles'' is restricted to Madagascar and the Comoros. In Madagascar, the two species are found in humid montane habitats, up to 1,500 m, in two disconnected areas in the north-east and south-east of the island. Fossils assignable to this genus have been found in New Zealand, suggesting a much wider distribution in the past. The conservation status of ''D. integrifolia'' has been assessed as of "least concern". Description Species are dioecious (i.e. "male" and "female" flowers occur on separate plants). Individual flowers have a very simple structure, without obvious petals or sepals. Female flowers have been interpreted in different ways, either as having two carpels or as occurring close together in pairs, each with a single carpel. ''Didymeles'' species are evergreen trees. The s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buxaceae
The Buxaceae are a small family of six genera and about 123 known species of flowering plants. They are shrubs and small trees, with a cosmopolitan distribution. A seventh genus, sometimes accepted in the past (''Notobuxus''), has been shown by genetic studies to be included within ''Buxus'' (Balthazar ''et al.'', 2000). The family is recognised by most taxonomists, and it is commonly known as the box family. However, its placement and circumscription has varied; some taxonomists treated '' Styloceras'' in its own family Stylocerataceae, ''Didymeles'' in its own family Didymelaceae, ''Haptanthus'' in Haptanthaceae (now all included in Buxaceae)), and formerly '' Simmondsia'' was included, which is not related and now usually placed in its own family Simmondsiaceae. The APG II system of 2003 recognises the family, but in a new circumscription in that it includes the genus ''Didymeles'' (two species of evergreen trees from Madagascar). However, APG II does allow the option of segr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tepal
A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very similar appearance), as in ''Magnolia'', or because, although it is possible to distinguish an outer whorl of sepals from an inner whorl of petals, the sepals and petals have similar appearance to one another (as in ''Lilium''). The term was first proposed by Augustin Pyramus de Candolle in 1827 and was constructed by analogy with the terms "petal" and "sepal". (De Candolle used the term ''perigonium'' or ''perigone'' for the tepals collectively; today, this term is used as a synonym for ''perianth''.) p. 39. Origin Undifferentiated tepals are believed to be the ancestral condition in flowering plants. For example, '' Amborella'', which is thought to have separated earliest in the evolution of flowering plants, has flowers with undiffer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 on the axis of a plant. The modifications can involve the length and the nature of the internodes and the phyllotaxis, as well as variations in the proportions, compressions, swellings, adnations, connations and reduction of main and secondary axes. One can also define an inflorescence as the reproductive portion of a plant that bears a cluster of flowers in a specific pattern. The stem holding the whole inflorescence is called a peduncle. The major axis (incorrectly referred to as the main stem) above the peduncle bearing the flowers or secondary branches is called the rachis. The stalk of each flower in the inflorescence is called a pedicel. A flower that is not part of an inflorescence is called a solitary flower and its stalk is al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 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 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 or instead of it. Examples of this type of bract include those of ''Euphorbia pulcherrima'' (poinsettia) and ''Bougainvillea'': both of these have large colourful bracts surrounding much smaller, less colourful flowers. In grasses, each floret (flower) is enclosed in a pair of papery bracts, called the lemma (lower bract) and p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollen
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of gymnosperms. If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. Individual pollen grains are small enough to require magnification to see detail. The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and forensics. Pollen in plants is used for transferring haploid male genetic material from the anther of a single flower to the stigma of another in cross-pollination. In a case of self-pollination, this process takes place from the anth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colpus
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of gymnosperms. If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. Individual pollen grains are small enough to require magnification to see detail. The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and forensics. Pollen in plants is used for transferring haploid male genetic material from the anther of a single flower to the stigma of another in cross-pollination. In a case of self-pollination, this process takes place from the anth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louis-Marie Aubert Du Petit-Thouars
Louis-Marie Aubert du Petit-Thouars (5 November 1758, Bournois – 12 May 1831, Paris) was an eminent French botanist known for his work collecting and describing orchids from the three islands of Madagascar, Mauritius and Réunion. Introduction Petit-Thouars came from an aristocratic family of the region of Anjou, where he grew up in the castle of Boumois, near Saumur. In 1792, after an imprisonment of two years during the French Revolution, he was exiled to Madagascar and the nearby islands such as La Réunion (then called Bourbon). He started collecting many plant specimens on Madagascar, Mauritius and La Réunion. Ten years later he was able to return to France with a collection of about 2000 plants. Most of his collection went to the ''Muséum de Paris'', while some species ended up at Kew. He was elected member of the prestigious ''Académie des Sciences'' on 10 April 1820. Du Petit-Thouars is remembered as the author of the book ''Histoire des végétaux recueill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stigma (botany)
The stigma () is the receptive tip of a carpel, or of several fused carpels, in the gynoecium of a flower. Description The stigma, together with the style and ovary (typically called the stigma-style-ovary system) comprises the pistil, which is part of the gynoecium or female reproductive organ of a plant. The stigma itself forms the distal portion of the style, or stylodia, and is composed of , the cells of which are receptive to pollen. These may be restricted to the apex of the style or, especially in wind pollinated species, cover a wide surface. The stigma receives pollen and it is on the stigma that the pollen grain germinates. Often sticky, the stigma is adapted in various ways to catch and trap pollen with various hairs, flaps, or sculpturings. The pollen may be captured from the air (wind-borne pollen, anemophily), from visiting insects or other animals ( biotic pollination), or in rare cases from surrounding water (hydrophily). Stigma can vary from long and sle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integument
In biology, an integument is the tissue surrounding an organism's body or an organ within, such as skin, a husk, shell, germ or rind. Etymology The term is derived from ''integumentum'', which is Latin for "a covering". In a transferred, or figurative sense, it could mean a cloak or a disguise. In English, "integument" is a fairly modern word, its origin having been traced back to the early seventeenth century; and refers to a material or layer with which anything is enclosed, clothed, or covered in the sense of "clad" or "coated", as with a skin or husk. Botanical usage In botany, the term "integument" may be used as it is in zoology, referring to the covering of an organ. When the context indicates nothing to the contrary, the word commonly refers to an envelope covering the nucellus of the ovule. The integument may consist of one layer (unitegmic) or two layers (bitegmic), each of which consisting of two or more layers of cells. The integument is perforated by a pore, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
