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Pentoxylales
Pentoxylales is an extinct order of seed plants known from the Jurassic and Early Cretaceous of East Gondwana. Discovery The first specimens belonging to Pentoxylales were reported by Birbal Sahni in 1948 from Jurassic-Cretaceous strata of the Rajmahal Hills of northeastern India. Remains have subsequently been reported from New Zealand, Australia and Antarctica. The oldest records of the group date to the Upper Jurassic, though there are unconfirmed Early Jurassic records. Morphology Stem The stem of Pentoxylales, referred to by the morphogenus '' Pentoxylon'', consists of 5 or 6 wedge shaped segments embedded within thin walled ground tissue. Leaves Leaves of Pentoxylales are of the strap shaped '' Taenopteris'' morphotype shared with other groups of seed plants, while leaves that preserve the cuticle are referred to the morphogenus '' Nipaniophyllum.'' The leaves are up to 20 centimetres long, and have a prominent midrib. Pollen organs The pollen organs of Pent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentoxylon
Pentoxylales is an extinct order of seed plants known from the Jurassic and Early Cretaceous of East Gondwana. Discovery The first specimens belonging to Pentoxylales were reported by Birbal Sahni in 1948 from Jurassic-Cretaceous strata of the Rajmahal Hills of northeastern India. Remains have subsequently been reported from New Zealand, Australia and Antarctica. The oldest records of the group date to the Upper Jurassic, though there are unconfirmed Early Jurassic records. Morphology Stem The stem of Pentoxylales, referred to by the morphogenus '' Pentoxylon'', consists of 5 or 6 wedge shaped segments embedded within thin walled ground tissue. Leaves Leaves of Pentoxylales are of the strap shaped '' Taenopteris'' morphotype shared with other groups of seed plants, while leaves that preserve the cuticle are referred to the morphogenus '' Nipaniophyllum.'' The leaves are up to 20 centimetres long, and have a prominent midrib. Pollen organs The pollen organs of Pentox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwana
Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zealandia, Arabian Peninsula, Arabia, and the Indian subcontinent. Gondwana was formed by the Accretion (geology), accretion of several cratons (large stable blocks of the Earth's crust), beginning with the East African Orogeny, the collision of India and Geography of Madagascar, Madagascar with East Africa, and culminating in with the overlapping Brasiliano orogeny, Brasiliano and Kuunga orogeny, Kuunga orogenies, the collision of South America with Africa, and the addition of Australia and Antarctica, respectively. Eventually, Gondwana became the largest piece of continental crust of the Paleozoic Era, covering an area of some , about one-fifth of the Earth's surface. It fused with Laurasia during the Carboniferous to form Pan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birbal Sahni
Birbal Sahni FRS (14 November 1891 – 10 April 1949) was an Indian paleobotanist who studied the fossils of the Indian subcontinent. He also took an interest in geology and archaeology. He founded what is now the Birbal Sahni Institute of Palaeobotany at Lucknow in 1946. His major contributions were in the study of the fossil plants of India and in plant evolution. He was also involved in the establishment of Indian science education and served as the president of the National Academy of Sciences, India and as an honorary president of the International Botanical Congress, Stockholm. Formative years Birbal Sahni was born in Bhera, Shahpur, in today's Pakistani Punjab, on 14 November 1891. He was the third child of Ishwar Devi and the pioneer Indian meteorologist and scientist Ruchi Ram Sahni who lived in Lahore. The family came from Dera Ismail Khan and they frequently made visits to Bhera which was close to the Salt Range and Khewra's geology may have interested Birbal at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bennettitales
Bennettitales (also known as cycadeoids) is an extinct order of seed plants that first appeared in the Permian period and became extinct in most areas toward the end of the Cretaceous. Bennettitales were amongst the most common seed plants of the Mesozoic, and had morphologies including shrub and cycad-like forms. The foliage of bennettitaleans is superficially nearly indistinguishable from that of cycads, but they are distinguished from cycads by their more complex flower-like reproductive organs, at least some of which were likely pollinated by insects. Although certainly gymnosperms ''sensu lato'' (cone-bearing seed plants), the relationships of bennettitaleans to other seed plants is debated. Their general resemblance to cycads is contradicted by numerous more subtle features of their reproductive systems and leaf structure. Some authors have linked bennettitaleans to angiosperms (flowering plants) and gnetophytes (a rare and unusual group of modern gymnosperms), forming a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrometre
The micrometre (English in the Commonwealth of Nations, Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System of Units (SI) equalling (SI standard prefix "micro-" = ); that is, one millionth of a metre (or one thousandth of a millimetre, , or about ). The nearest smaller common SI Unit, SI unit is the nanometre, equivalent to one thousandth of a micrometre, one millionth of a millimetre or one billionth of a metre (). The micrometre is a common unit of measurement for wavelengths of infrared radiation as well as sizes of biological cell (biology), cells and bacteria, and for grading wool by the diameter of the fibres. The width of a single human hair ranges from approximately 20 to . Examples Between 1 μm and 10 μm: * 1–10 μm – length of a typical bacterium * 3–8 μm – width of str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossopteris
''Glossopteris'' (etymology: from Ancient Greek γλῶσσα (glôssa, " tongue ") + πτερίς (pterís, " fern ")) is the largest and best-known genus of the extinct Permian order of seed plants known as Glossopteridales (also known as Arberiales, Ottokariales, or Dictyopteridiales). The name ''Glossopteris'' refers only to leaves, within the framework of form genera used in paleobotany, used for leaves of plants belonging to the glossopterid family Dictyopteridiaceae. Species of ''Glossopteris'' were the dominant trees of the middle to high-latitude lowland vegetation, often in swampy environments, across Gondwana (which at this time formed the southern part of Pangaea) during the Permian Period. ''Glossopteris'' fossils were critical in recognizing former connections between the various fragments of Gondwana: South America, Africa, India, Australia, New Zealand, and Antarctica. The ''Glossopteris'' forest ecosystems became extinct as part of the end-Permian mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bramble
''Rubus'' is a large and diverse genus of flowering plants in the rose family, Rosaceae, subfamily Rosoideae, most commonly known as brambles. Fruits of various species are known as raspberries, blackberries, dewberries, and bristleberries. It is a diverse genus, with the estimated number of ''Rubus'' species varying from 250 to over 1000, found across all continents except Antarctica. Most of these plants have woody stems with prickles like roses; spines, bristles, and gland-tipped hairs are also common in the genus. The ''Rubus'' fruit, sometimes called a bramble fruit, is an aggregate of drupelets. The term ''cane fruit'' or ''cane berry'' applies to any ''Rubus'' species or hybrid which is commonly grown with supports such as wires or canes, including raspberries, blackberries, and hybrids such as loganberry, boysenberry, marionberry and tayberry. The stems of such plants are also referred to as ''canes''. Description Bramble bushes typically grow as shrubs (though ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liana
A liana is a long-Plant stem, stemmed Woody plant, woody vine that is rooted in the soil at ground level and uses trees, as well as other means of vertical support, to climb up to the Canopy (biology), canopy in search of direct sunlight. The word ''liana'' does not refer to a Taxonomy (biology), taxonomic grouping, but rather a habit of plant growth—much like ''tree'' or ''shrub''. It comes from standard French , itself from an Antilles French dialect word meaning to sheaf (agriculture), sheave. Ecology Lianas are characteristic of Tropical and subtropical moist broadleaf forests, tropical moist broadleaf forests (especially Tropical seasonal forest, seasonal forests), but may be found in temperate rainforests and temperate deciduous forests. There are also temperate lianas, for example the members of the ''Clematis'' or ''Vitis'' (wild grape) genera. Lianas can form bridges in the forest canopy, providing Arboreal locomotion, arboreal animals—including ants and many ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only plants that are usable as lumber, or only plants above a specified height. But wider definitions include taller palms, tree ferns, bananas, and bamboos. Trees are not a monophyletic taxonomic group but consist of a wide variety of plant species that have independently evolved a trunk and branches as a way to tower above other plants to compete for sunlight. The majority of tree species are angiosperms or hardwoods; of the rest, many are gymnosperms or softwoods. Trees tend to be long-lived, some trees reaching several thousand years old. Trees evolved around 400 million years ago, and it is estimated that there are around three trillion mature trees in the world currently. A tree typically has many secondary branches supported cle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habit (biology)
Habit, equivalent to habitus in some applications in biology, refers variously to aspects of behaviour or structure, as follows: *In zoology (particularly in ethology), ''habit'' usually refers to aspects of more or less predictable ''behaviour'', instinctive or otherwise, though it also has broader application. ''Habitus'' refers to the characteristic form or morphology of a species. *In botany, the plant habit is the characteristic form in which a given species of plant grows.Jackson, Benjamin, Daydon; A Glossary of Botanic Terms with their Derivation and Accent; Published by Gerald Duckworth & Co. London, 4th ed 1928 Behavior In zoology, ''habit'' (not to be confused with ''habitus'' as described below) usually refers to a specific behavior pattern, either adopted, learned, pathological, innate, or directly related to physiology. For example: * ...the atwas in the ''habit'' of springing upon the oor knockerin order to gain admission... * If these sensitive parrots are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flower
Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, modified leaves; corolla, the petals; androecium, the male reproductive unit consisting of stamens and pollen; and gynoecium, the female part, containing style and stigma, which receives the pollen at the tip of the style, and ovary, which contains the ovules. When flowers are arranged in groups, they are known collectively as inflorescences. Floral growth originates at stem tips and is controlled by MADS-box genes. In most plant species flowers are heterosporous, and so can produce sex cells of both sexes. Pollination mediates the transport of pollen to the ovules in the ovaries, to facilitate sexual reproduction. It can occur between different plants, as in cross-pollination, or between flowers on the same plant or even the same f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
