The term evergreen is from the Latin perennis , durable, perennial, and folium , leaf. This flora also called evergreen or evergreen because, although there is in cool-season areas, always keeps the foliage .
It is used to designate trees or bushes that have leaves alive throughout the year , as opposed to the term deciduous . In the latter, all the leaves die each year to reach the unfavorable season and return to sprout new leaves on arrival of the favorable season. In the trees of persistent foliage, however, only killed some of the leaves each year and other, younger, remain on the ground and bind to the new ones spring up each spring, so the life span of each leaf can last several years (if each leaf is longer than two years, says that the blade is perennial) and the cup never appears naked.

Botanically, an annual plant is a plant that germinates, flowers and succumbs in the course of a year . The annual true only survive year after year for their seeds . Some species seeded year can still be considered but ultimately not flourish. 1
In gardening are considered annual plants growing outdoors in spring and summer and surviving just one growing season.
Many food plants are annual, or cultivated as such, including most cereal domesticated. Some perennials and biennials are grown as annuals for convenience, particularly if they are less resistant to local climate. carrot , celery and parsley are true biennials grown as annuals for their edible roots, petioles and leaves, respectively. The tomato , the sweet potatoes and peppers are perennials that are often sensitive cultivar year.
The annual ornamental plants are called bed and are widely used in gardens to provide flashes of color, tend to a longer flowering season than herbaceous perennials. Some perennials grown as annuals are impatiens , begonia , Antirrhinum , Pelargonium , Solenostemon and petunia . Some biennials behave as annuals are the violet and rose trembling Alcea rosea .
The life cycle of a year may develop in less than a month in some species, and for many months in others. The turnip ( Brassica rapa ) does in five weeks under fluorescent lights in the laboratory. Many annual ephemeral desert are called 2 due to its multiplication cycle in a few weeks. And a lot of energy to survive the dry condition.

Winter annuals germinate in fall or winter, live through the winter and bloom in winter or spring. Plants grow and bloom during the cold season, when most plants are dormant and other annual seeds are waiting for warm weather to germinate. Winter annuals die after flowering, leaving seeds, and they are waiting to germinate until the soil temperature is cool again in the fall or winter. Winter annuals typically grow at ground level, where they are more protected in the very cold nights, and take advantage of short periods to grow temperate winter when the snow melts.
Lamiun , Stellaria and Barbarea are winter annuals. These are important ecologically, and vegetative cover to prevent soil erosion during the winter and early spring when there is no cover, and vegetation provide animals and birds that feed on them.
While gardeners often seen as weeds, this is not entirely correct, since many of them die when the soil temperature warms again in spring, while other plants are dormant and still have no leaves. Although not directly compete with cultivated plants, they are sometimes considered a pest in commercial agriculture, because they can harbor pests or fungal diseases of insects (Microbotryum sp) which then attack the crops. Ironically, providing protection against soil erosion can also be a problem for commercial agriculture.







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