Pear

-

Pear, name for a fruit tree of the genus Pyrus of the family Rosaceae (rose family) and for its fruit, a pome. The common pear (P. communis) is one of the earliest cultivated of fruit trees, both in its native W Asia and in Europe. Most of the pear strains grown for their sweet and juicy fruit are varieties of P. communis or of its hybrids with other species of Pyrus—usually P. pyrifolia, known as the Japanese, Chinese, or sand pear and indigenous to China. The main use of the sand pear today is as a rootstock in pear orchards; the related quince is used for the same purpose. Pear strains with fruit of really good eating quality were not developed until the 18th and 19th cent. in N Europe, whence almost all the present successful varieties (e.g., the Bartlett and Seckel) grown in the United States (chiefly on the Pacific coast and in the Great Lakes area) were directly imported. European production is far greater—especially in Germany, France, and Switzerland, where much of the crop is used for making pear cider (perry). Pears are also cultivated on a large scale in Japan, Turkey, Argentina, and Australia. They are usually sold fresh or canned; some are dried. Several varieties of the common pear and of other species—e.g., the small, white-foliaged snow pear (P. nivalis)—are cultivated as ornamentals, and pear wood, hard and dense, is used to a limited extent in cabinetmaking. The pear tree and its fruit are similar to the closely related apple (considered by some botanists to be of the same genus) in characteristics and in method of cultivation, but the tree is somewhat less hardy and the fruit more perishable. Pear or fire blight is the tree's most serious disease; it is also attacked by several insect pests. Pears are classified in the division Magnoliophyta, class Magnoliopsida, order Rosales, family Rosaceae.

Comments

Post a Comment

Popular posts from this blog

Monocot and Dicot Seeds

-
Image
Monocotyledons (monocots) and dicotyledons (dicots) make up the two large groups of flowering plants, differentiated by their seed structures. Monocot seeds contain one cotyledon, or embryonic leaf. When these seeds germinate, the cotyledon remains below ground, absorbing nutrients from the endosperm, the starchy food supply in the seed. The coytledon transports these nutrients to the developing seedling. Dicot seeds contain two coytledons, which absorb and store the nutrients from the endosperm before the seed germinates. The cotyledons, thick with stored nutrients, emerge above ground during germination, and then transport the stored nutrients to the developing seedling. For a brief time, the cotyledons also serve as the first photosynthesizing leaves, but they wither and die when the true leaves emerge. related articles: flower flower variations in structure flower sexual reproduction flower pollination and fertilization flowering and the life cycle evolution of flowers angios
Read more

Gymnosperm

-
Image
Gymnosperm (Latin gymn-, “naked”; Greek sperma, “seed”), is a common name for any seed-bearing vascular plant without flowers. There are several types: the cycad , ginkgo , conifer , yew , and gnetophyte. Gymnosperms are woody plants, either shrubs, trees, or, rarely, vines (some gnetophytes). They differ from the other phylum of seed plants, the flowering plants (see Angiosperm ), in that the seeds are not enclosed in carpels but rather are borne upon seed scales arranged in cones. The gymnosperms are the most ancient seed plants; they appear to have arisen from fern ancestors in the Devonian Period. Cycads retain the most primitive characters of the extant seed plants. Gnetophytes are considered from morphological and molecular evidence to share a common ancestry with the flowering plants. Living gymnosperms are distributed worldwide, with a majority, particularly the conifers, in temperate and subarctic regions. Cycads and gnetophytes are mainly tropical to subtropical. There are ab
Read more

Cedar Tree

-
Image
Cedar (tree) is a common name for three or four species of large trees native to mountainous areas of North Africa and Asia. Cedar trees belong to the pine family, the members of which have needlelike leaves and, like all conifers, bear their seeds on scales clustered into cones. They differ from other members of the family in their evergreen four-angled leaves borne on short side-branches. The genus produces fragrant, durable, red-colored wood used in construction and cabinetry. The name cedar is also applied to other conifer trees with fragrant wood (see Cypress ). The well-known white cedar grows in swamps of the eastern United States and reaches a height of 24 m (80 ft). An arborvitae is also called cedar; western cedar and eastern white cedar are both important timber trees in the United States. Eastern red cedar, widespread in the eastern United States, is a juniper . A flowering tropical American mahogany is known as Spanish or West Indian cedar. Incense Cedar Native to wester
Read more