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Arachnoid (botany)
Arachnoid organs, such as leaves or stems, have an external appearance similar to cobwebs – the appearance of being covered with fine, white, usually tangled hairs. This can cause plants to appear grey or white. The arachnoid appearance is common on the leaves and stems of various sclerophyllous members of the family Asteraceae, such as some thistle Thistle is the common name of a group of flowering plants characterized by leaves with sharp spikes on the margins, mostly in the family Asteraceae. Prickles can also occur all over the planton the stem and on the flat parts of the leaves. T ...s. The arachnoid appearance of '' Haworthia arachnoidea'' arises from the spinescent leaf denticles, and the arachnoid appearance of the cactus '' Cephalocereus senilis'' is from long-lasting hairy spines. See also * Arachnoid (other) References Plant morphology {{plant-morphology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cobweb
A spider web, spiderweb, spider's web, or cobweb (from the archaic word '' coppe'', meaning 'spider') is a structure created by a spider out of proteinaceous spider silk extruded from its spinnerets, generally meant to catch its prey. Spider webs have existed for at least 100 million years, as witnessed in a rare find of Early Cretaceous amber from Sussex, in southern England. Many spiders build webs specifically to trap and catch insects to eat. However, not all spiders catch their prey in webs, and some do not build webs at all. The term "spider web" is typically used to refer to a web that is apparently still in use (i.e., clean), whereas "cobweb" refers to a seemingly abandoned (i.e., dusty) web. However, the word "cobweb" is also used by biologists to describe the tangled three-dimensional web of some spiders of the family Theridiidae. While this large family is known as the cobweb spiders, they actually have a huge range of web architectures; other names for this spider f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Biodiversity Heritage Library
The Biodiversity Heritage Library (BHL) is the world’s largest open-access digital library for biodiversity literature and archives. BHL operates as a worldwide consortium of natural history, botanical, research, and national libraries working together to address this challenge by digitizing the natural history literature held in their collections and making it freely available for open access as part of a global "biodiversity community". The BHL consortium works with the international taxonomic community, publishers, bioinformaticians, and information technology professionals to develop tools and services to facilitate greater access, interoperability, and reuse of content and data. BHL provides a range of services, data exports, and APIs to allow users to download content, harvest source data files, and reuse materials for research purposes. Through taxonomic intelligence tools developed by Global Names Architecture, BHL indexes the taxonomic names throughout the collection, al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Sclerophyllous
Sclerophyll is a type of vegetation that is adapted to long periods of dryness and heat. The plants feature hard leaves, short internodes (the distance between leaves along the stem) and leaf orientation which is parallel or oblique to direct sunlight. Sclerophyllous plants occur in many parts of the world, but are most typical of areas with low rainfall or seasonal droughts, such as Australia, Africa, and western North and South America. They are prominent throughout Australia, parts of Argentina, the Cerrado biogeographic region of Bolivia, Paraguay and Brazil, and in the Mediterranean biomes that cover the Mediterranean Basin, California, Chile, and the Cape Province of South Africa. In the Mediterranean basin, holm oak, cork oak and olives are typical hardwood trees. In addition, there are several species of pine under the trees in the vegetation zone. The shrub layer contains numerous herbs such as rosemary, thyme and lavender. In relation to the potential natural veg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Asteraceae
Asteraceae () is a large family (biology), family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the Order (biology), order Asterales. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger family is unclear as the quantity of Extant taxon, extant species in each family is unknown. The Asteraceae were first described in the year 1740 and given the original name Composita, Compositae. The family is commonly known as the aster, Daisy (flower), daisy, composite, or sunflower family. Most species of Asteraceae are herbaceous plants, and may be Annual plant, annual, Biennial plant, biennial, or Perennial plant, perennial, but there are also shrubs, vines, and trees. The family has a widespread distribution, from subpolar to tropical regions, in a wide variety of habitats. Most occur in Hot desert climate, hot desert and cold or hot Semi-arid climate, semi-desert climates, and they are found on ever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Thistle
Thistle is the common name of a group of flowering plants characterized by leaves with sharp spikes on the margins, mostly in the family Asteraceae. Prickles can also occur all over the planton the stem and on the flat parts of the leaves. These prickles protect the plant from herbivores. Typically, an involucre with a clasping shape similar to a cup or urn subtends each of a thistle's flower heads. The typically feathery pappus of a ripe thistle flower is known as thistle-down. The spininess varies considerably by species. For example, '' Cirsium heterophyllum'' has very soft spines while '' Cirsium spinosissimum'' is the opposite. Typically, species adapted to dry environments are more spiny. The term thistle is sometimes taken to mean precisely those plants in the tribe Cardueae (synonym: Cynareae), especially the genera '' Carduus'', '' Cirsium'', and '' Onopordum''. However, plants outside this tribe are sometimes also called thistles. Biennial thistles are partic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Haworthia Arachnoidea
''Haworthia arachnoidea'', locally known as "papierrosie" (paper-rose) or "spinnekopnes" (spider-nest), is the type species of the genus ''Haworthia'', in the family Asphodelaceae, in the Western Cape Province of South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O .... Description The plant has numerous dark green leaves, covered in translucent bristles, in a dense rosette. The leaves themselves are without translucent tips, unlike some other ''Haworthia'' species. The rosettes dry and contract in the arid summers. It is sometimes confused with the widespread '' Haworthia decipiens'' (''decipiens = deceptive'') which occurs in the Great Karoo to the east. However ''H. decipiens'' has shorter, flatter, wider leaves; a lighter colour; translucent leaf tips; larger and spars ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Thorns, Spines, And Prickles
In plant morphology, thorns, spines, and prickles, and in general spinose structures (sometimes called ''spinose teeth'' or ''spinose apical processes''), are hard, rigid extensions or modifications of leaf, leaves, roots, plant stem, stems, or plant bud, buds with sharp, stiff ends, and generally serve the same function: physically plant defense against herbivory, defending plants against herbivory. Description In common language, the terms are used more or less interchangeably, but in botanical terms, thorns are derived from Shoot (botany), shoots (so that they may or may not be branched, they may or may not have leaves, and they may or may not arise from a bud),Simpson, M. G. 2010. "Plant Morphology". In: ''Plant Systematics, 2nd. edition''. Elsevier Academic Press. Chapter 9.Judd, Campbell, Kellogg, Stevens, Donoghue. 2007. "Structural and Biochemical Characters". In: ''Plant Systematics, a phylogenetic approach, third edition''. Chapter 4. spines are derived from Leaf, leaves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cephalocereus Senilis
''Cephalocereus senilis'', the old man cactus, is a species of cactus native to Hidalgo and Veracruz in central Mexico. It is threatened in the wild, but widespread propagation and popularity in cultivation have reduced the demand on wild populations. Description ''Cephalocereus senilis'' is a tall, columnar species with clusters of stems that may grow to 5–15 m tall; the individual stems are usually unbranched, being unable to withstand the weight of side branches adequately. The most striking feature is the shaggy coat of long, white hairs suggestive of unkempt hair on an old man. The coat is a particularly striking silvery white on the young cactus; as the plant ages the stem begins to lose its covering. The flowers are red, yellow, or white, though the plant may not flower until 10–20 years old. Morphology and function of the coat The hairs are modified spines and they make many a plant appear almost snow-white; they serve to protect the plant from frost and sun. However ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Eriocephalus Africanus
''Eriocephalus africanus'' is a bushy shrublet indigenous to South Africa. It has a wide distribution in the Western and Eastern Cape Floral Region, Cape, and in Namaqualand. The plant has several common names in various languages. It is known as the Kapokbossie or Wild Rosemary (Afrikaans "wilde roosmaryn") referring to its fancied resemblance to rosemary. The superficial resemblance is in the foliage, which, though softer and not glossy, grows in a habit similar to that of the common Mediterranean rosemary, although the two species are not related. ''Eriocephalus africanus'' is fragrant, with lightly felted foliage that gives the plant a matt silvery appearance. The inflorescences are small brown and pale yellow heads borne in corymbs; each head bears a few bisexual ray florets with abortive ovaries and snowy white petals that practically cover a bush in flower. The ray florets surround usually some four to eight female florets in the centre.Dyer, R. Allen, The Genera of Sou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Gazania
''Gazania'' is a genus of flowering plants in the family Asteraceae, native to Southern Africa.Per Ola Karis. 2007. "Arctotideae" pages 200-207. In: Klaus Kubitzki (series editor); Joachim W. Kadereit and Charles Jeffrey (volume editors). ''The Families and Genera of Vascular Plants'' volume VIII. Springer-Verlag: Berlin; Heidelberg, Germany. They produce large, daisy-like composite flowerheads in brilliant shades of yellow and orange, over a long period in summer. They are often planted as drought-tolerant groundcover. Taxonomic history The genus was first formally described by German botanist Joseph Gaertner in the second volume of his major work ''De Fructibus et Seminibus Plantarum'' in 1791. Gaertner named the genus after Theodorus Gaza, a 15th-century translator of the works of Theophrastus.Seranne Howis, Nigel P. Barker, and Ladislav Mucina. 2009. "Globally grown, but poorly known: species limits and biogeography of ''Gazania'' Gaertn. (Asteraceae) inferred from chlo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Felted
A felted material is a hairy or Wikt:filamentous, filamentous (hairy-like) fibre that is densely packed or tangled, forming felt or felt-like structures. Advantages of felted tissue The dermis is described in Gray's Anatomy as "felted connective tissue, with a varying amount of elastic fibers and numerous blood vessels, lymphatics, and nerves." When describing the external coat of an artery (the ''Tunica externa (vessels), tunica adventitia''), Gray said that it "...consists mainly of fine and closely felted bundles of white connective tissue..." In such classes of connective tissue the felted structure helps with resistance to tearing by distributing localised Stress (mechanics), stresses, and it imparts Shock (mechanics), shock absorption and Elastic modulus, elasticity in two or three dimensions at once regardless of the shape of the tissue. In other words, certain types of felting can yield controllable isotropy or anisotropy in the behaviour of a structure. Zoology Mamm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Arachnoid (other) '', an arcade game
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Arachnoid may refer to: * Relating to arachnids * Arachnoid (astrogeology), a geological structure found only on the planet Venus * Arachnoid (botany), referring to organs with a cobwebby exterior appearance * Arachnoid granulation, small protrusions of the arachnoid mater * Arachnoid mater, a layer of the meninges, membranes that contain the central nervous system See also * ''Arkanoid is a 1986 Block kuzushi, block breaker arcade game developed and published by Taito. In North America, it was published by Romstar. Controlling a paddle-like craft known as the Vaus, the player is tasked with clearing a formation of colorful blo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
