|
Phyllotaxis
In botany, phyllotaxis () or phyllotaxy is the arrangement of leaf, leaves on a plant stem. Phyllotactic spirals form a distinctive class of patterns in nature. Leaf arrangement The basic leaf#Arrangement on the stem, arrangements of leaves on a stem are opposite and alternate (also known as spiral). Leaves may also be Whorl (botany), whorled if several leaves arise, or appear to arise, from the same level (at the same Node (botany), node) on a stem. With an opposite leaf arrangement, two leaves arise from the stem at the same level (at the same Node (botany), node), on opposite sides of the stem. An opposite leaf pair can be thought of as a whorl of two leaves. With an alternate (spiral) pattern, each leaf arises at a different point (node) on the stem. Distichous phyllotaxis, also called "two-ranked leaf arrangement" is a special case of either opposite or alternate leaf arrangement where the leaves on a stem are arranged in two vertical columns on opposite sides of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patterns In Nature
Patterns in nature are visible regularities of form found in the natural world. These patterns recur in different contexts and can sometimes be modelled mathematically. Natural patterns include symmetries, trees, spirals, meanders, waves, foams, tessellations, cracks and stripes. Early Greek philosophers studied pattern, with Plato, Pythagoras and Empedocles attempting to explain order in nature. The modern understanding of visible patterns developed gradually over time. In the 19th century, the Belgian physicist Joseph Plateau examined soap films, leading him to formulate the concept of a minimal surface. The German biologist and artist Ernst Haeckel painted hundreds of marine organisms to emphasise their symmetry. Scottish biologist D'Arcy Thompson pioneered the study of growth patterns in both plants and animals, showing that simple equations could explain spiral growth. In the 20th century, the British mathematician Alan Turing predicted mechanisms of morphogenesis which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leaf
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, flower, and fruit collectively form the shoot system. In most leaves, the primary photosynthetic tissue is the palisade mesophyll and is located on the upper side of the blade or lamina of the leaf but in some species, including the mature foliage of ''Eucalyptus'', palisade mesophyll is present on both sides and the leaves are said to be isobilateral. Most leaves are flattened and have distinct upper (adaxial) and lower ( abaxial) surfaces that differ in color, hairiness, the number of stomata (pores that intake and output gases), the amount and structure of epicuticular wax and other features. Leaves are mostly green in color due to the presence of a compound called chlorophyll that is essential for photosynthesis as it absorbs light ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decussate
Decussation is used in biological contexts to describe a crossing (due to the shape of the Roman numeral for ten, an uppercase 'X' (), ). In Latin anatomical terms, the form is used, e.g. . Similarly, the anatomical term chiasma is named after the Greek uppercase 'Χ' (chi). Whereas a decussation refers to a crossing within the central nervous system, various kinds of crossings in the peripheral nervous system are called chiasma. Examples include: * In the brain, where nerve fibers obliquely cross from one lateral side of the brain to the other, that is to say they cross at a level other than their origin. See for examples Decussation of pyramids and sensory decussation. In neuroanatomy, the term ''chiasma'' is reserved for crossing of- or within nerves such as in the optic chiasm. * In botanical leaf taxology, the word ''decussate'' describes an opposite pattern of leaves which has successive pairs at right angles to each other (i.e. rotated 90 degrees along the stem when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brabejum Stellatifolium
''Brabejum'' is a genus of a single species of large evergreen tree, ''Brabejum stellatifolium'' in the family Proteaceae, commonly called wild almond, bitter almond or ghoeboontjie. It is restricted in the wild to South Africa's Western Cape province, where it grows in thickets along the banks of streams. The plant is of botanical interest as being Africa's only member of the large grevilleoid subfamily. It is a bushy small tree with branches widely at ground level and numerous erect vigorous stems. Leaves grow up to 6 in (15 cm) long, narrow and bluntly toothed, appear at intervals along the branches, mostly in whorls of 6. In summer, the plant bears white flowers densely crowded on spikes arising from rusty buds at the leaf axils. The fruits to 2 in (5 cm) long, magenta to reddish brown, similar to an almond, appear in autumn. The nut is too bitter to eat; however, in earlier times it was boiled, roasted, and ground to make a "coffee" drink. This tree has special sig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crassulaceae
The Crassulaceae (from Latin ''crassus'', thick), also known as the stonecrop family or the orpine family, are a diverse family of dicotyledon flowering plants characterized by succulent leaves and a unique form of photosynthesis, known as Crassulacean acid metabolism (CAM). Flowers generally have five floral parts. Crassulaceae are usually herbaceous but there are some subshrubs, and relatively few treelike or aquatic plants. Crassulaceae are a medium size monophyletic family in the core eudicots, among the order Saxifragales, whose diversity has made infrafamilial classification very difficult. The family includes approximately 1,400 species and 34–35 genera, depending on the circumscription of the genus ''Sedum'', and distributed over three subfamilies. Members of the Crassulaceae are found worldwide, but mostly in the Northern Hemisphere and southern Africa, typically in dry and/or cold areas where water may be scarce, although a few are aquatic. Crassulaceae are mainly pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithops
''Lithops'' is a genus of succulent plants in the ice plant family, Aizoaceae. Members of the genus are native to southern Africa. The name is derived from the Ancient Greek words () 'stone' and () 'face', referring to the stone-like appearance of the plants. They avoid being eaten by blending in with surrounding rocks and are often known as pebble plants or living stones. The formation of the name from the Ancient Greek ''-ops'' means that even a single plant is called a Lithops. Description Individual ''Lithops'' plants consist of one or more pairs of bulbous, almost fused leaves opposite to each other and hardly any stem. The slit between the leaves contains the meristem and produces flowers and new leaves. The leaves of ''Lithops'' are mostly buried below the surface of the soil, with a partially or completely translucent top surface known as a leaf window which allows light to enter the interior of the leaves for photosynthesis. During winter a new leaf pair, or occa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conophytum
''Conophytum'' is a genus of South African and Namibian succulent plants that belong to the family Aizoaceae. The name is derived from the Latin ''conus'' (cone) and Greek ''phytum'' (plant). The plants are also known as knopies (buttons in Afrikaans), waterblasies (water blisters in Afrikaans), sphaeroids, conos, cone plants, dumplings, or button plants. Taxonomy The genus is sometimes wrongly referred to as ''Conophyton'', the name that Adrian Hardy Haworth suggested in 1821: "If this section proves to be a genus, the name of Conophyton would be apt". However, this was too tentative to establish a validly published generic name and also, Haworth himself neither adopted it nor accepted the genus. The genus was neither recognised nor validly named until the name ''Conophytum'' was published 101 years later. Description ''Conophytum'' species are dwarf cushion-forming or single-bodied succulents. Members of the genus are tiny plants with succulent leaves ranging from 1/4" to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crassula Rupestris-PICT3087
''Crassula'' is a genus of succulent plants containing about 200 accepted species, including the popular jade plant (''Crassula ovata''). They are members of the stonecrop family (Crassulaceae) and are native to many parts of the globe, but cultivated varieties originate almost exclusively from species from the Eastern Cape of South Africa. Crassulas are usually propagated by stem or leaf cuttings. Most cultivated forms will tolerate some small degree of frost, but extremes of cold or heat will cause them to lose foliage and die. Taxonomy ''Crassula'' was first formally described by Carl Linnaeus in 1753 with 10 species. Etymology The name crassula comes from the Latin adjective ''crassus'', meaning thick, referring to the thickening of the succulent leaves. List of selected species *''Crassula alata'' *'' Crassula alba'' *''Crassula alpestris'' (Sand-Coated Crassula) *'' Crassula alstonii'' *''Crassula aquatica'' (common pigmyweed, water pygmyweed) *''Crassula arboresc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internode (botany)
A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, stores nutrients, and produces new living tissue. The stem can also be called halm or haulm. The stem is normally divided into nodes and internodes: * The nodes hold one or more leaves, as well as buds which can grow into branches (with leaves, conifer cones, or flowers). Adventitious roots may also be produced from the nodes. * The internodes distance one node from another. The term "shoots" is often confused with "stems"; "shoots" generally refers to new fresh plant growth including both stems and other structures like leaves or flowers. In most plants stems are located above the soil surface but some plants have underground stems. Stems have four main functions which are: * Support for and the elevation of leaves, flowers, and fruits. The stems ke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatomical Terms Of Location
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and anatomical axes. The meaning of terms that are used can change depending on whether an organism is bipedal or quadrupedal. Additionally, for some animals such as invertebrates, some terms may not have any meaning at all; for example, an animal that is radially symmetrical will have no anterior surface, but can still have a description that a part is close to the middle ("proximal") or further from the middle ("distal"). International organisations have determined vocabularies that are often used as standard vocabularies for subdisciplines of anatom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macadamia
''Macadamia'' is a genus of four species of trees in the flowering plant family Proteaceae. They are indigenous to Australia, native to northeastern New South Wales and central and southeastern Queensland specifically. Two species of the genus are commercially important for their fruit, the macadamia nut (or simply macadamia). Global production in 2015 was . Other names include Queensland nut, bush nut, maroochi nut, bauple nut and Hawaii nut. In Australian Aboriginal languages, the fruit is known by names such as ''bauple'', ''gyndl'' or ''jindilli'' (north of Great Dividing Range) and ''boombera'' (south of the Great Range). It was an important source of bushfood for the Aboriginal peoples who are the original inhabitants of the area. The nut was first commercially produced on a wide scale in Hawaii, where Australian seeds were introduced in the 1880s, and for some time, they were the world's largest producer. South Africa has been the world's largest producer of the maca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.png "Click for more on -> Leaf")
(cropped).JPG "Click for more on -> Lithops")
.jpg "Click for more on -> Macadamia")