free download PNG images :Cucumber

Cucumis sativus is a widely planted plant in Cucurbitaceae. This is a kind of creeping vine, which grows cucumber like fruits used as vegetables. There are three main varieties of cucumber: sliced, pickled and seedless. Of these varieties, several have been created. In North America, the term "wild cucumber" refers to echinocystis and Marah plants, but there is no close relationship between them. Cucumbers originally came from South Asia, but now they grow on most continents. Many different types of cucumbers are traded on the global market.

Cucumber is a kind of creeping vine, which is rooted on the ground and grows into a lattice or other support frame, surrounded by small spiral tendrils. The plant may also be born in a soilless medium, and if there is no support, it will spread along the ground. The vines have large leaves and form a crown on the fruit. The fruit of a typical cucumber variety is roughly cylindrical, but tapered at the end, as long as 60 cm (24 in.) and as high as 10 cm (3.9 in.) in diameter. Classified as pepo, a plant berry with a hard outer skin and no internal cracks. Like tomatoes and pumpkins, it is often used as a vegetable to sense, prepare and eat. Cucumber fruit is made up of 95% water (see nutrition table).

A few cucumber varieties are parthenocarpic, and will produce seedless fruits after flowering without pollination. Pollination of these varieties reduces quality. In the United States, these are usually grown in greenhouses that do not include bees. In Europe, they grow outdoors in some areas, not bees.

However, most cucumber varieties are seeded and need pollination. For this reason, thousands of beehives are transported to cucumber fields every year. Bumblebees and several other bees may also pollinate cucumbers. Most cucumbers that need pollination are self incompatible, so they need to use the pollen of another plant to form seeds and fruits. There are some self compatible varieties related to "lemon" varieties. Symptoms of underpollination include miscarriage and malformed fruit. Some pollinated flowers may produce green fruits and develop normally near the stem end, but they are pale yellow and wither at the flower end.

Traditional varieties first produce male flowers in approximately equal numbers, then female flowers. The new monoecious hybrid can produce almost all female flowers. They may have planted a pollen pollination variety, with an increase in the number of hives per unit area, but the temperature changes even induce male flowers on these plants, which may be enough to cause pollination.

The cucumber that grows into fresh food is called sliced cucumber. The main varieties of slicers mature on vines with large leaves to provide shade. They are mainly eaten in immature green, because mature yellow usually turns sour. The slicers that are commercially grown for the North American market are generally longer, smoother, more uniform in color, and have much stronger skin. Other countries have smaller slicers, thin and delicate skins, usually fewer seeds, and are sold in plastic skins for protection. Sometimes these are called English cucumbers. The variety may also be called "telegraph cucumber," especially in Australia. Cucumber slices can also be pickled.

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