The ancestors of flowering plants diverged from gymnosperms around 245–202 million years ago, and the first flowering plants known to exist are from 160 million years ago. They diversified enormously during the Lower Cretaceous and became widespread around 120 million years ago, but replaced conifers as the dominant trees only around 60–100 million years ago. Angiosperm derived characteristics Flowers The flowers, which are the reproductive organs of flowering plants, are the most remarkable feature distinguishing them from the other seed plants. Flowers aid angiosperms by enabling a wider range of adaptability and broadening the ecological niches open to them. These distinguishing characteristics taken together have made the angiosperms the most diverse and numerous land plants and the most commercially important group to humans. Evolution In 2013 flowers encased in amber were found and dated 100 million years before present. Classification
Unassigned Angiospermae Classification System: APG III (down to family level) Main Page Regnum: Plantae Cladus: Angiosperms Circulus: Unassigned Angiospermae Familiae: Genera: †Macclintockia References Angiosperm Phylogeny Group (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III".Classification APG IIIUn article de Wikipédia, l'encyclopédie libre. La classification APG III (2009), ou classification phylogénétique, est la troisième version de classification botanique des angiospermes établie par l'Angiosperms Phylogeny Group. C'est la classification botanique la plus importante aujourd'hui. Elle est une modification de la classification APG II (2003). Comme la classification APG et la classification APG II, cette classification est construite à la base de deux gènes chloroplastiques et un gène nucléaire de ribosome, mais ces données sont complétées dans quelques cas par d'autres données. APG III selon Mark W. En octobre 2009, alors que l'Angiosperm Phylogeny Group publiait APG III, deux des membres de l'APG, Mark W. Ce document semble actuellement être assez suivi sur internet. Tropicos (Rosaceae y est placé dans Rosanae. Classification résumée[modifier | modifier le code] Classification détaillée (avec toutes les familles)[modifier | modifier le code] Légende:
Search also olive plantHow a Photographer Created Images of Fireworks Unlike Any You've Ever Seen - Megan GarberA photographer's experiment puts explosions in new light. A spaceship? A sea creature? A spunky chapeau? Nope: fireworks. Earlier this month, David Johnson found himself at the International Fireworks Show in Ottawa, Canada. The resulting images, which I first saw on the blog This Is Colossal, are mesmerizing. As Johnson later told me of his method: The way I captured the photos was actually pretty simple... it just required good timing. It does! A dandelion: A group of dandelions: A sunflower: Thistles: Spores: Viruses: An armored insect: You can see more over at Johnson's website, here. Via Steve Silberman and This Is Colossal.
GymnospermClassification In early classification schemes, the gymnosperms (Gymnospermae) were regarded as a "natural" group. There is conflicting evidence on the question of whether the living gymnosperms form a clade. The fossil record of gymnosperms includes many distinctive taxa that do not belong to the four modern groups, including seed-bearing trees that have a somewhat fern-like vegetative morphology (the so-called "seed ferns" or pteridosperms.) When fossil gymnosperms such as Bennettitales, Caytonia and the glossopterids are considered, it is clear that angiosperms are nested within a larger gymnosperm clade, although which group of gymnosperms is their closest relative remains unclear. For the most recent classification on extant gymnosperms see Christenhusz et al. (2011). Subclass Cycadidae Order CycadalesFamily Cycadaceae: CycasFamily Zamiaceae: Dioon, Bowenia, Macrozamia, Lepidozamia, Encephalartos, Stangeria, Ceratozamia, Microcycas, Zamia. Subclass Ginkgoidae
Botanical NomenclatureNomenclature Nomenclature refers to the naming of things. Botanical nomenclature is (surprise) about naming plants. Bear in mind that plant names refer to abstract entities - the collection of all plants (past, present, and future) that belong to the same group. As you will recall, taxonomy is about grouping. Botanical nomenclature is about applying names to taxonomic groups. Scientific names of plants reflect the taxonomic group to which the plant belongs. Scientific names are never misleading. Pronunciation. Taxonomy refers to forming groups. If people are going to communicate around the world, there needs to be an internationally accepted system of nomenclature. Towards an International Code Pre-Linnaean Practices 1) Names were formed like Latin words. 2) Once a name had been attached to a plant group, it should not be given another name. 3) When commenting on how a name was to be interpreted, one should list the names of others that had used it. Other Codes Agreement, at last 2. Form.
OliveThe olive ( i/ˈɒlɪv/ or Its fruit, also called the olive, is of major agricultural importance in the Mediterranean region as the source of olive oil. Description 19th century illustration The olive tree, Olea europaea, is an evergreen tree or shrub native to the Mediterranean, Asia and Africa. The small white, feathery flowers, with ten-cleft calyx and corolla, two stamens and bifid stigma, are borne generally on the previous year's wood, in racemes springing from the axils of the leaves. The fruit is a small drupe 1–2.5 cm (0.39–0.98 in) long, thinner-fleshed and smaller in wild plants than in orchard cultivars. Taxonomy There are six natural subspecies of Olea europaea distributed over a wide range: The subspecies maroccana and cerasiformis are respectively hexaploid and tetraploid. Wild growing forms of the olive are sometimes treated as the species Olea oleaster. Cultivars History Prehistory The immediate ancestry of the cultivated olive is unknown.
A small (but glorious) world: The best microscope images of 2012Most people know Nikon as a purveyor of pro and consumer-grade digital cameras. But the company's expertise with optics bleeds over into related markets—it's one of the science community's major suppliers of microscopes. And each year the company asks the community to send it some of their favorite images of tiny objects. A panel of scientists and journalists have chosen the best of this past year's submissions, which Nikon has placed on its Small World site. We've gone through and picked out some of our favorite images from this year, and Nikon provided some high-resolution versions. The grand prize winner at top highlights the blood vessels as they form in the brain of a zebrafish. Confocals only capture light from a single plane of focus, so each individual image is like an optical slice through the tissue. Lynx spiders are a very successful genus, with members found on every continent. Cancer's an ugly disease, but damn, this image of a cancerous cell looks good.