Kids Research Express

Spike Moss, common name for a medium-size family of primitive vascular plants. The plants are mainly of tropical distribution, growing in moist, shaded habitats. A few occur in deserts, where they become dormant during the driest parts of the year; the resurrection plant is an example of such a species. The plants of the spike moss genus are similar to those of a related genus (see Club Moss ), but in the spike moss a small outgrowth, called a ligule, is located on the upper surface of each leaf close to where it joins the stem. The spike moss is heterosporous. That is, it reproduces through the production of two kinds of spores, produced in sacs called sporangia, that are borne by specialized leaves called sporophylls. Small sacs, or microsporangia, produce many small microspores, which germinate to form short-lived, nongreen microgametophytes that produce sperm (male sexual cells). Larger sacs, or megasporangia, produce a few larger megaspores each, and these form nongreen megagamet...

Resurrection Plant, common name for a fernlike, perennial desert plant, of the family of spike mosses, that ranges from the southwestern United States down to El Salvador. The flowerless plant has small, scalelike leaves and grows to a height of 10 cm (4 in). It requires little water to survive, but when completely deprived of moisture it contracts into a ball and may be borne by the wind. When it settles near water, it unfolds and is renewed—hence the name. In their dried-up state, resurrection plants are sometimes sold as novelties. The plant is sometimes called the rose of Jericho , just as that plant is often called the resurrection plant. Scientific classification: The resurrection plant belongs to the family Selaginellaceae. It is classified as Selaginella lepidophylla.

Rose of Jericho, also resurrection plant , common name for a small herb of the mustard family, native to Syria. It is seldom more than 15 cm (6 in) high and has small white flowers. After the herb has flowered, the leaves fall off and the branches become incurved toward the center, so that the plant assumes an almost globular form. In this state it is often blown about by the wind in the desert. When it happens to be blown into water the branches expand again, and the pods open and spill out the seeds. Scientific classification: The rose of Jericho belongs to the family Brassicaceae (formerly Cruciferae). It is classified as Anastatica

Club Moss, common name for a group of plants closely related to the ferns . Two important genera are low, sometimes creeping evergreen plants that are widely distributed throughout the United States and other temperate and tropical climates. Various tropical species grow on the trunks of trees or on the ground. Usually less than 30 cm (less than 12 in) tall, the plants resemble pine in that their leaves are needlelike. Their widespread use in Christmas wreaths has brought some species close to extinction. In reproduction, spores and asexual cells borne in an elongated cone are scattered on the ground and ripen underground into sexual reproductive organs from which new plants grow. The common club moss, also called running pine and stag's horn moss, grows in open, dry woods and rocky places. Ground pine or ground cedar has branchlets that resemble the branches of juniper. Tree moss, fir club moss, or foxfeet grows on rocks and in bogs. Fossil species, many of gigantic size, have b...

Spores are usually produced by the division of cells within a structure called a sporangium. In bryophytes and most ferns, horsetails, club mosses, and whisk ferns, spores give rise to the same kind of plants as the parents, which are thus called homosporous. But in a few of those just mentioned and in all seed plants, some spores grow into sexual plants (gametophytes) that produce male gametes (sex cells), while others grow into sexual plants that produce female gametes; parent plants producing such spores are called heterosporous. Spores that give rise to male gametophytes are called microspores; spores giving rise to female gametophytes are known as megaspores. In seed plants, male gametophytes are known as pollen grains, and female gametophytes are called embryo sacs. Thick-walled resting zygotes (cells formed by the union of gametes) resemble spores and are called zygospores or oospores.

Shrub, short, woody plant, typically with several stems arising from or near the ground. Shrubs are perennial plants—that is, they live for at least three years. Although the distinction is often artificial, shrubs are generally shorter and have more stems than trees . Shrubs grow wild in all but the coldest or driest regions of the earth. They may be evergreen (retaining foliage throughout the year) or deciduous (losing foliage each year). Shrubs are often planted to control erosion, the wearing away of topsoil by wind and rain, in exposed areas. Their variety of forms, foliage, flowers, fruits, and fragrance make them popular in gardens and as landscape plants. According to 20th century British botanist Stanley Whitehead, shrubs “have the stable, long-life qualities of forest trees without the embarrassment of the latter’s size. They match the floral beauty and grace of habit of herbaceous plants without their compelling need for support and attention.” Popular shrubs include the rho...

Rhododendron, common name for flowering plants of a genus of the heath family. The genus contains some 850 species, the majority of which are cultivated. Native to the temperate areas of the Northern Hemisphere, rhododendrons are most abundant in the Himalayas, southeast Asia, and the mountains of Malaysia. Cultivated species can now be found on all continents. Rhododendrons exhibit great variety in size, habit, and flower color. They range from small, ground-hugging shrubs to small trees, and from white to pink, dark-purple, or yellow flowers. Most species are evergreen—that is, they retain their foliage throughout the year. The deciduous species of rhododendron, those that lose all of their foliage each year, are known in horticulture as azaleas. Scientific classification: Rhododendrons make up the genus Rhododendron of the family Ericaceae.