In botany, a seed is a plant embryo and food reserve enclosed in a protective outer covering called a seed coat (testa). More generally, the term "seed" means anything that can be sown, which may include seed and husk or tuber. Seeds are the product of the ripened ovule, after the embryo sac is fertilized by sperm from pollen, forming a zygote. The embryo within a seed develops from the zygote and grows within the mother plant to a certain size before growth is halted.
Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta, also known as Coniferophyta or Coniferae. The division contains a single extant class, Pinopsida. All extant conifers are perennial woody plants with secondary growth. The great majority are trees, though a few are shrubs. Examples include cedars, Douglas-firs, cypresses, firs, junipers, kauri, larches, pines, hemlocks, redwoods, spruces, and yews. As of 2002, Pinophyta contained seven families, 60 to 65 genera, and more than 600 living species.
The Namib is a coastal desert in Southern Africa. According to the broadest definition, the Namib stretches for more than 2,000 kilometres (1,200 mi) along the Atlantic coasts of Angola, Namibia, and northwest South Africa, extending southward from the Carunjamba River in Angola, through Namibia and to the Olifants River in Western Cape, South Africa. The Namib's northernmost portion, which extends 450 kilometres (280 mi) from the Angola-Namibia border, is known as Moçâmedes Desert, while its southern portion approaches the neighboring Kalahari Desert. From the Atlantic coast eastward, the Namib gradually ascends in elevation, reaching up to 200 kilometres (120 mi) inland to the foot of the Great Escarpment. Annual precipitation ranges from 2 millimetres (0.079 in) in the aridest regions to 200 millimetres (7.9 in) at the escarpment, making the Namib the only true desert in southern Africa. Having endured arid or semi-arid conditions for roughly 55–80 million years, the Namib may be the oldest desert in the world and contains some of the world's driest regions, with only western South America's Atacama Desert to challenge it for age and aridity benchmarks.
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.
Gnetophyta is a division of plants, grouped within the gymnosperms, that consists of some 70 species across the three relict genera: Gnetum, Welwitschia, and Ephedra. The earliest unambiguous records of the group date to the Jurassic, and they achieved their highest diversity during the Early Cretaceous. The primary difference between gnetophytes and other gymnosperms is the presence of vessel elements, a system of small tubes (xylem) that transport water within the plant, similar to those found in flowering plants. Because of this, gnetophytes were once thought to be the closest gymnosperm relatives to flowering plants, but more recent molecular studies have brought this hypothesis into question, with many recent phylogenies finding them to be nested within the conifers.
The gymnosperms are a group of seed-producing plants that includes conifers, cycads, Ginkgo, and gnetophytes, forming the clade Gymnospermae. The term gymnosperm comes from the composite word in Greek: γυμνόσπερμος, literally meaning 'naked seeds'. The name is based on the unenclosed condition of their seeds. The non-encased condition of their seeds contrasts with the seeds and ovules of flowering plants (angiosperms), which are enclosed within an ovary. Gymnosperm seeds develop either on the surface of scales or leaves, which are often modified to form cones, or on their own as in yew, Torreya, Ginkgo. Gymnosperm lifecycles involve alternation of generations. They have a dominant diploid sporophyte phase and a reduced haploid gametophyte phase which is dependent on the sporophytic phase. The term "gymnosperm" is often used in paleobotany to refer to all non-angiosperm seed plants. In that case, to specify the modern monophyletic group of gymnosperms, the term Acrogymnospermae is sometimes used.
Araucaria bidwillii, commonly known as the bunya pine (, or bunya-bunya, is a large evergreen coniferous tree in the family Araucariaceae which is endemic to Australia. Its natural range is southeast Queensland with two very small, disjunct populations in northeast Queensland's World Heritage listed Wet Tropics. There are many planted specimens on the Atherton Tableland, in New South Wales, and around the Perth metropolitan area, and it has also been widely planted in other parts of the world. They are very tall trees – the tallest living individual is in Bunya Mountains National Park and was reported by Robert Van Pelt in January 2003 to be 51.5 m in height.
Friedrich Martin Josef Welwitsch was an Austrian explorer and botanist who in Angola was the first European to describe the plant 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.
A conifer cone or pinecone is a seed-bearing organ on gymnosperm plants. It is usually woody, ovoid to globular, including scales and bracts arranged around a central axis, especially in conifers and cycads. The cone of Pinophyta contains the reproductive structures. The woody cone is the female cone, which produces plants. The male cone, which produces pollen, is usually herbaceous and much less conspicuous even at full maturity. The name "cone" derives from Greek konos, which also gave name to the geometric cone. The individual plates of a cone are known as scales. The umbo of a conifer cone refers to the first year's growth of a seed scale on the cone, showing up as a protuberance at the end of the two-year-old scale.
Gnetum is a genus of gymnosperms, the sole genus in the family Gnetaceae within the Gnetophyta. They are tropical evergreen trees, shrubs and lianas. Unlike other gymnosperms, they possess vessel elements in the xylem. Some species have been proposed to have been the first plants to be insect-pollinated as their fossils occur in association with extinct pollinating scorpionflies. Molecular phylogenies based on nuclear and plastid sequences from most of the species indicate hybridization among some of the Southeast Asian species. Fossil-calibrated molecular-clocks suggest that the Gnetum lineages now found in Africa, South America and Southeast Asia are the result of ancient long-distance dispersal across seawater.
Bennettitales 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.
The Kaokoveld Desert is a coastal desert of northern Namibia and southern Angola.
Welwitschiaceae is a family of plants of the order Gnetales with one living species, Welwitschia mirabilis, found in southwestern Africa. Three fossil genera have been recovered from the Crato Formation – late Aptian strata located in the Araripe Basin in northeastern Brazil, with one of these also being known from the early Late Cretaceous (Cenomanian-Turonian) Akrabou Formation of Morocco.
Iona National Park is the largest and oldest national park in Angola. It is situated in the Southwestern corner of the country, in Namibe Province. It is roughly bound by the Atlantic Ocean to the West, an escarpment to the East that marks the beginning of the interior plateau, the Curoca River to the North, and the Cunene River to the South. It is about 200 kilometres (120 mi) south of the city of Namibe and covers 5,850 square miles (15,200 km2) sq. miles.
Acanthosicyos horridus is an unusual melon that is endemic to the Namib desert. In English it is known as Nara, butter-nuts, or butterpips; in one of the Khoisan languages it is locally called ǃnaras or ǃnara.
A seed plant or spermatophyte, also known as a phanerogam or a phaenogam, is any plant that produces seeds. It is a category of embryophyte that includes most of the familiar land plants, including the flowering plants and the gymnosperms, but not ferns, mosses, or algae.
The Moçâmedes Desert is a desert located in the deep southwest of Angola, near the border with Namibia. The desert forms the northern tip of the Namib Desert. From the Atlantic Ocean in the west, the desert gradually rises to a semiarid plain where African ironwood trees grow. Few people live in the desert; communities are found mainly in small fishing towns on the coast. The unique tumboa, a desert plant with a short, wide trunk and two gigantic leaves that can survive for a century, is endemic to the desert. Little water is present in the desert surface.
Araucaria mirabilis is an extinct species of coniferous tree from Patagonia, Argentina. It belongs to the genus Araucaria.
The Pavilhão Welwitschia Mirabilis is a state-owned multisports indoor arena located in Moçâmedes, Angola. The 3072-seat arena, features hardwood flooring, electronic scoreboard and a wide range of features that makes it one of the most modern of its kind in Africa. was built to host the 2013 World Roller Hockey World Championship alongside the Pavilhão Multiusos de Luanda. It is fit for such sports as Basketball, Handball, Volleyball and Roller Hockey.
Probergrothius angolensis, sometimes known as the Welwitschia bug, is a species of true bug found in the Namib desert and nearby regions.
