Monday, March 5, 2012
The generic name derives from ακακία (akakia), the name given by early Greek botanist-physician Pedanius Dioscorides (ca. 40-90) to the medicinal tree A. nilotica in his book Materia Medica.This name derives from the Greek word for its characteristic thorns, ακις (akis, thorn).The species name nilotica was given by Linnaeus from this tree's best-known range along the Nile river.
Acacias are also known as thorntrees, whistling thorns or wattles, including the yellow-fever acacia and umbrella acacias.
The genus Acacia previously contained roughly 1300 species, about 960 of them native to Australia, with the remainder spread around the tropical to warm-temperate regions of both hemispheres, including Europe, Africa, southern Asia, and the Americas. However, in 2005 the genus was divided into five separate genera. The name Acacia was retained for the majority of the Australian species and a few in tropical Asia, Madagascar and Pacific Islands. Most of the species outside Australia, and a small number of Australian species, were reclassified into Vachellia and Senegalia. The two final genera, Acaciella and Mariosousa, only contain about a dozen species from the Americas each.
Sunday, March 4, 2012
A third, extinct species, N. aureavallis, is known from Eocene fossils from North Dakota, United States.
Saturday, March 3, 2012
Many Christians see the star as a miraculous sign to mark the birth of the Christ (or messiah). Some theologians claimed that the star fulfilled a prophecy, known as the Star Prophecy.Astronomers have made several attempts to link the star to unusual astronomical events, such as a conjunction of Jupiter and Saturn, a comet or a supernova.
Prominent scholars question the historical accuracy of the story and argue that the star was a pious fiction created by the author of the Gospel of Matthew.
The subject is a favorite at planetarium shows during the Christmas season, although the Biblical account suggests that the visit of the magi took place at least several months after Jesus was born.[nb 1] The visit is traditionally celebrated on Epiphany (January 6) in Western Christianity.The star often appears in representations of the manger scene found in Luke, although the star and the wise men do not appear in Luke's nativity story.
Iris is a genus of 260-300 species of flowering plants with showy flowers. It takes its name from the Greek word for a rainbow, referring to the wide variety of flower colors found among the many species. As well as being the scientific name, iris is also very widely used as a common name for all Iris species, though some plants called thus belong to other closely related genera. A common name for some species is 'flags', while the plants of the subgenus Scorpiris are widely known as 'junos', particularly in horticulture. It is a popular garden flower.
The genera Belamcanda (blackberry lily), Hermodactylus (snake's head iris), Neomarica (walking iris) and Pardanthopsis are sometimes included in Iris.
Lilium is a genus of herbaceous flowering plants growing from bulbs, all with large prominent flowers. They comprise a genus of about 110species in the lily family Liliaceae. Most species are native to the temperate northern hemisphere, though the range extends into the northern subtropics.
Lilies form an important group of flowering garden plants, and are important culturally and in literature in much of the world. Some species are sometimes grown or harvested for the edible bulbs.
The species in this genus are the true lilies. Many other plants exist with "lily" in the common English name, some of which are quite unrelated to the true lilies.
Bougainvillea, is the name of a group of South American shrubs and climbing vines. They grow to a height of 10 feet (3 meters) or more. They have small flowers that are enclosed by large, colorful bracts(modified leaves). The bracts may be red, purple, pink, orange, or pale yellow.They are often grown as porch climbers in the South and in California, and for hedges in South America. They must be kept in greenhouses in colder climates because frost kills them. They are raised from sterns cut from older plants