|
Tumboa
''Welwitschia'' is a monotypic genus of gnetophytes containing only the species ''Welwitschia mirabilis''. It is named after the Austrian botanist Friedrich Welwitsch, who documented the plant in the 1850s. In common use, it is sometimes referred to as the tree tumbo. It is native to Angola and Namibia, where it grows in the extreme conditions of the Namib desert, tolerating high heat and low precipitation. ''Welwitschia'' is the only living genus of the family Welwitschiaceae and order Welwitschiales, and is one of three extant genera of gnetophytes, alongside ''Gnetum'' and '' Ephedra''. ''Welwitschia'' is well known for its unique morphology. The plant only has two leaves that grow out of a large woody stem, dubbed a crown, and continue to grow over the plant's entire life. ''Welwitschia'' is one of the longest-living plants on Earth, with some individuals being thousands of years old. As such, the leaves can become quite large, often reaching several meters in length. Like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedrich Welwitsch
Friedrich Martin Josef Welwitsch (25 February 1806 – 20 October 1872) was an Austrian Empire, Austrian exploration, explorer and botany, botanist who in Angola was the first European to describe the plant ''Welwitschia, Welwitschia mirabilis''. His report received wide attention among the botanists and general public, comparable only to the discovery of two other plants in the 19th century, namely ''Victoria amazonica'' and ''Rafflesia arnoldii''.Strlič, Matija. "Dr. Friderik Velbič, 1806–1872". ''Proteus, the journal of the Natural Sciences Society of Slovenia''. Year 61, No. 9/10 (pp. 396-404). ISSN 0033-1805. In Angola, Welwitsch also discovered ''Rhipsalis baccifera'', the only cactus species naturally occurring outside the New World. It was found a few years later in Sri Lanka too, which reignited the now already one-and-a-half-century-old debate on the origin of cacti in Africa and Asia. At the time, the debate concluded with the conviction of numerous authors that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hook
A hook is a tool consisting of a length of material, typically metal, that contains a portion that is curved/bent back or has a deeply grooved indentation, which serves to grab, latch or in any way attach itself onto another object. The hook's design allows traction forces to be relayed through the curved/indented portion to and from the proximal end of the hook, which is either a straight shaft (known as the hook's ''shank'') or a ring (sometimes called the hook's "''eye''") for attachment to a thread (yarn), thread, rope or chain, providing a reversible attachment between two objects. In many cases, the distal end of the hook is sharply pointed to enable penetration into the target material, providing a firmer anchorage. Some hooks, particularly fish hooks, also have a ''barb'', a backwards-pointed projection near the pointed end that functions as a secondary "mini-hook" to catch and trap surrounding material, ensuring that the hook point cannot be easily pulled back out once e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South African National Biodiversity Institute
The South African National Biodiversity Institute (SANBI) is an organisation tasked with research and dissemination of information on biodiversity, and legally mandated to contribute to the management of the country's biodiversity resources. It was established in 2004 in terms of the National Environmental Management: Biodiversity Act, No 10 of 2004, under the South African Department of Environmental Affairs (later named Department of Forestry, Fisheries and the Environment). History SANBI was established on 1 September 2004 in terms of the National Environmental Management: Biodiversity Act, No 10 of 2004. Previously, in 1989, the autonomous statutory National Botanical Institute (NBI) had been formed from the National Botanic Gardens and the Botanical Research Institute, which had been founded in the early 20th century to study and conserve the South African flora. The mandate of the National Botanical Institute was expanded by the act to include the full diversity of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiocarbon Dating
Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for Chronological dating, determining the age of an object containing organic material by using the properties of carbon-14, radiocarbon, a radioactive Isotopes of carbon, isotope of carbon. The method was developed in the late 1940s at the University of Chicago by Willard Libby. It is based on the fact that radiocarbon () is constantly being created in the Atmosphere of Earth, Earth's atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and thereafter the amount of it contains begins to decrease as the undergoes radioactive decay. Measuring the amount of in a sample from a dead plant or animal, such as a piece of w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meristem
In cell biology, the meristem is a structure composed of specialized tissue found in plants, consisting of stem cells, known as meristematic cells, which are undifferentiated cells capable of continuous cellular division. These meristematic cells play a fundamental role in plant growth, regeneration, and acclimatization, as they serve as the source of all differentiated plant tissues and organs. They contribute to the formation of structures such as fruits, leaves, and seeds, as well as supportive tissues like stems and roots. Meristematic cells are totipotent, meaning they have the ability to differentiate into any plant cell type. As they divide, they generate new cells, some of which remain meristematic cells while others differentiate into specialized cells that typically lose the ability to divide or produce new cell types. Due to their active division and undifferentiated nature, meristematic cells form the foundation for the formation of new plant organs and the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vascular Plant
Vascular plants (), also called tracheophytes (, ) or collectively tracheophyta (; ), are plants that have lignin, lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified Tissue (biology), tissue (the phloem) to conduct products of photosynthesis. The group includes most embryophyte, land plants ( accepted known species) excluding mosses. Vascular plants include the clubmosses, Equisetum, horsetails, ferns, gymnosperms (including conifers), and angiosperms (flowering plants). They are contrasted with nonvascular plants such as mosses and green algae. Scientific names for the vascular plants group include Tracheophyta, Tracheobionta and Equisetopsida sensu lato, Equisetopsida ''sensu lato''. Some early land plants (the rhyniophytes) had less developed vascular tissue; the term eutracheophyte has been used for all other vascular plants, including all living ones. Historically, vascular plants were known as "hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Stem
A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaf, leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, engages in photosynthesis, stores nutrients, and produces new living tissue. The stem can also be called the culm, halm, haulm, stalk, or thyrsus. The stem is normally divided into nodes and internodes: * The nodes are the points of attachment for leaves and can hold one or more leaves. There are sometimes axillary buds between the stem and leaf which can grow into branches (with leaf, leaves, conifer cones, or inflorescence, flowers). Adventitious roots (e.g. brace roots) may also be produced from the nodes. Vines may produce tendrils from nodes. * The internodes distance one node from another. The term "Shoot (botany), shoots" is often confused with "stems"; "shoots" generally refers to new fresh plant growth, including both stems and other str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leaf
A leaf (: leaves) is a principal appendage of the plant stem, stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, flower, and fruit collectively form the Shoot (botany), shoot system. In most leaves, the primary Photosynthesis, photosynthetic Tissue (biology), 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. The leaf is an integral part of the stem system, and most leaves are flattened and have distinct upper (Glossary of botanical terms#adaxial, adaxial) and lower (Glossary of botanical terms#abaxial, abaxial) surfaces that differ in color, Trichome, hairiness, the number of stomata (pores that intake and output gases), the amount and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cotyledon
A cotyledon ( ; ; "a cavity, small cup, any cup-shaped hollow", gen. (), ) is a "seed leaf" – a significant part of the embryo within the seed of a plant – and is formally defined as "the embryonic leaf in seed-bearing plants, one or more of which are the first to appear from a germinating seed." Botanists use the number of cotyledons present as one characteristic to classify the flowering plants (angiosperms): species with one cotyledon are called monocotyledonous ("monocots"); plants with two embryonic leaves are termed dicotyledonous ("dicots"). Many orchids with minute seeds have no identifiable cotyledon, and are regarded as acotyledons. The Dodders (''Cuscuta'' spp) also lack cotyledons, as does the African tree '' Mammea africana'' ( Calophyllaceae). In the case of dicot seedlings whose cotyledons are photosynthetic, the cotyledons are functionally similar to leaves. However, true leaves and cotyledons are developmentally distinct. Cotyledons form during embryo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germination
Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, ferns, bacteria, and the growth of the pollen tube from the pollen grain of a seed plant. Seed plants Germination is usually the growth of a plant contained within a seed resulting in the formation of the seedling. It is also the process of reactivation of metabolic machinery of the seed resulting in the emergence of radicle and plumule. The seed of a vascular plant is a small package produced in a fruit or cone after the union of male and female reproductive cells. All fully developed seeds contain an embryo and, in most plant species some store of food reserves, wrapped in a seed coat. Dormant seeds are viable seeds that do not germinate because they require specific internal or environmental stimuli to resume growth. Und ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herero Language
Herero (Otjiherero) is a Bantu language spoken by the Herero and Mbanderu peoples in Namibia and Botswana, as well as by small communities of people in southwestern Angola. There were speakers in these countries between 2015 and 2018. Distribution Its linguistic distribution covers a zone called Hereroland, which is constituted of the region of Omaheke along with the Otjozondjupa and Kunene Regions. The Himba people, who are related to the Herero and Mbanderu, speak a dialect very close to Otjiherero. Many Herero-speakers live in Windhoek, the capital of Namibia. Phonology Consonants The sounds /f s l/ are found in loanwords. Vowels Script Because of the translation of missionary Gottlieb Viehe (1839–1901) of the Bible into Herero, at the end of the 19th century, the spoken language was transcribed to an alphabet based on the Latin script. Father Peter Heinrich Brincker (1836–1904) translated several theological works and songs. Orthography * a - �* b - ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Khoekhoe Language
Khoekhoe or Khoikhoi ( ; , ), also known by the ethnic terms Nama ( ; ''Namagowab''), Damara (''ǂNūkhoegowab''), or Nama/Damara and formerly as Hottentot, is the most widespread of the non- Bantu languages of Southern Africa that make heavy use of click consonants and therefore were formerly classified as Khoisan, a grouping now recognized as obsolete. It belongs to the Khoe language family, and is spoken in Namibia, Botswana, and South Africa primarily by three ethnic groups: Namakhoen, ǂNūkhoen, and Haiǁomkhoen. History The Haiǁom, who had spoken a Juu language, later shifted to Khoekhoe. The name for the speakers, '' Khoekhoen'', is from the word ''khoe'' "person", with reduplication and the suffix ''-n'' to indicate the general plural. Georg Friedrich Wreede was the first European to study the language, after arriving in ǁHui!gaeb (later Cape Town) in 1659. Status Khoekhoe is a national language in Namibia. In Namibia and South Africa, state-owned broadcas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
