วันอาทิตย์ที่ 28 ธันวาคม พ.ศ. 2551

Sunflowers




The sunflower is an annual plant in the family Asteraceae and native to the Americas, with a large flowering head . The stem can grow as high as 3 meters and the flower head can reach 30 cm in diameter with the "large" seeds. The term "sunflower" is also used to refer to all plants of the genus Helianthus, many of which are perennial plants.




Cultivation and uses
To grow well, sunflowers need full sun. They grow best in fertile, moist, well-drained soil with a lot of mulch. In commercial planting, seeds are planted 45 cm apart and 2.5 cm deep.
Sunflower "whole seed" are sold as a snack food, after roasting in ovens, with or without salt added. Sunflowers can be processed into a peanut butter alternative, Sunbutter, especially in China, Russia, the United States, the Middle East and Europe. In Germany, it is mixed together with rye flour to make Sonnenblumenkernbrot , which is quite popular in Germanspeaking Europe. It is also sold as food for birds and can be used directly in cooking and salads.
Sunflower oil, extracted from the seeds, is used for cooking, as a carrier oil and to produce margarine and biodiesel, as it is cheaper than olive oil. A range of sunflower varieties exist with differing fatty acid compositions; some 'high oleic' types contain a higher level of healthy monounsaturated fats in their oil than even olive oil.

Tulips




Tulipa, commonly called tulip, is a genus of about 150 species of bulbous flowering plants in the family Liliaceae. The native range of the species includes southern Europe, north Africa, and Asia from Anatolia and Iran in the west to northeast of China. The centre of diversity of the genus is in the Pamir and Hindu Kush mountains and the steppes of Kazakhstan. A number of species and many hybrid cultivars are grown in gardens, used as pot plants or as fresh cut flowers. Most of the cultivated species, subspecies and cultivars of tulip are derived from Tulipa gesneriana.
Cultivation

Tulip Festival in Woodburn, Oregon. 2007

Wild tulip in the steppes of Kazakhstan
Tulips originate from mountainous areas with temperate climates and need a period of cool dormancy. They do best in climates with long cool springs and early summers, but they are often grown as spring blooming annual plantings in warmer areas of the world. The bulbs are typically planted in late summer and fall, normally from 10 to 20 cm (4 to 8 in.) deep, depending of the type planted, in well draining soils. In parts of the world that do not have long cool springs and early summers, the bulbs are often planted up to 12 inches deep; this provides some protection from the heat of summer and tends to force the plants to regenerate one large bulb each year instead of many smaller non blooming ones. This can extend the usefulness of the plants in warmer areas a few years but not stave off the degradation in bulb size and eventual death of the plants.


วันอาทิตย์ที่ 21 ธันวาคม พ.ศ. 2551

Attraction methods of flowers







Plants can not move from one location to another, thus many flowers have evolved to attract animals to transfer pollen between individuals in dispersed populations. Flowers that are insect-pollinated are called entomophilous; literally "insect-loving" in Latin. They can be highly modified along with the pollinating insects by co-evolution. Flowers commonly have glands called nectaries on various parts that attract animals looking for nutritious necta. Birds and bees have color vision, enabling them to seek out "colorful" flowers. Some flowers have patterns, called nectar guides, that show pollinators where to look for nectar; they may be visible only under ultraviolet light, which is visible to bees and some other insects. Flowers also attract pollinators by scent and some of those scents are pleasant to our sense of smell. Not all flower scents are appealing to humans, a number of flowers are pollinated by insects that are attracted to rotten flesh and have flowers that smell like dead animals, often called Carrion flowers including Rafflesia, the titan arum, and the North American pawpaw (Asimina triloba). Flowers pollinated by night visitors, including bats and moths, are likely to concentrate on scent to attract pollinators and most such flowers are white.
Still other flowers use mimicry to attract pollinators. Some species of orchids, for example, produce flowers resembling female bees in color, shape, and scent. Male bees move from one such flower to another in search of a mate.






วันศุกร์ที่ 19 ธันวาคม พ.ศ. 2551

วันพุธที่ 17 ธันวาคม พ.ศ. 2551




General knowledge about flower







A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants. The biological function of a flower is to mediate the union of male sperm with female ovum in order to produce seeds. The process begins with pollination, is followed by fertilization, leading to the formation and dispersal of the seeds. For the higher plants, seeds are the next generation, and serve as the primary means by which individuals of a species are dispersed across the landscape. The grouping of flowers on a plant are called the inflorescence.
In addition to serving as the reproductive organs of flowering plants, flowers have long been admired and used by humans, mainly to beautify their environment but also as a source of food.