Kids Research Express

Mistletoe, common name for the Loranthaceae, a family of chiefly tropical hemiparasitic herbs and shrubs with leathery evergreen leaves and waxy white berries. They have green leaves, but they manufacture only part of the nutrients they require. Mistletoes are aerial hemiparasites, attaching themselves to their hosts by modified roots called haustoria, with which they absorb water and food from the host. The list of hosts is varied and numerous. Mistletoes are widely used for Christmas decoration. The custom of kissing under a branch of mistletoe apparently originated among the Druids and other early Europeans, to whom mistletoe was sacred. From early times it has been associated with folklore and superstition; it was thought to cure many ills. The mistletoe most widely sold in America is Phoradendron flavescens; most popular in Europe is the "true" mistletoe, Viscum album of the related family Viscacceae, which is parasitic especially on apple trees. An American genus (Arceu...

Cone or strobilus (strŏb`ələs), in botany, reproductive organ of the gymnosperms (the conifers , cycads , and ginkgoes ). Like the flower in the angiosperms (flowering plants), the cone is actually a highly modified branch; unlike the flower, it does not have sepals or petals. Usually separate male (staminate, or pollen) cones and female (ovulate, or seed) cones are borne on the same plant. Each of the numerous scales, or sporophylls, of the staminate cone bears pollen and each female-cone scale bears ovules in which egg cells are produced. In the pine, a conifer, the staminate cones are small and short-lived; they are borne in clusters at the top of the tree. At the time of pollination, enormous numbers of pollen grains are released and dispersed by wind; those that land accidentally on female-cone scales extend pollen tubes part way into the ovule during one growing season but usually do not reach the stage of actual fertilization until the next year. The cones that are commonly obse...

Pine, common name for members of the Pinaceae, a family of resinous woody trees with needlelike, usually evergreen leaves. The Pinaceae reproduce by means of cones (see cone ) rather than flowers and many have winged seeds, suitable for wind distribution. They are found chiefly in north temperate regions, where they form vast forests. The family was apparently more abundant in the mid-Cenozoic era, but it has maintained its population better than other gymnosperms because the trees are more adaptable to cold, dry climates; the reduced leaf surface and deep-set stomata minimize loss of water by transpiration. The family is the largest and most important of the conifers, providing naval stores, paper pulp, and more lumber by far than any other family. In some localities almost pure stands occur, permitting economical lumbering of large numbers of a given type of tree. Of the family's nine genera four are widely dispersed throughout North America and the Old World. Members of all nine...

Nectarine, name for a tree (Prunus persica var. nectarina) of the family Rosaceae (rose family) and for its fruit, a smooth-skinned variety of the peach. The nectarine is a classical example of bud variation (see mutation). The nectarine tree occasionally produces peaches, and the peach tree nectarines. In appearance, culture, and care the nectarine is almost identical to the peach. It is cultivated in north temperate zones of both hemispheres, in America chiefly in the mild Pacific coastal area. The nectarine has been known for at least 2,000 years; in the 16th cent. it was called the nut of Persia. Nectarines are classified in the division Magnoliophyta, class Magnoliopsida, order Rosales, family Rosaceae.