Kids Research Express

Vegetative Reproduction, method by which plants reproduce asexually—that is, without the union of cells or nuclei of cells—thus producing individuals that are genetically identical to the parent. Vegetative reproduction takes place either by fragmentation or by special asexual structures. Parts of liverworts and mosses fragment from the parent and grow into new individuals, as do plant cuttings. Asexual structures in plants include specialized stems such as tubers, stolons (runners), rhizomes, and corms, and specialized buds such as bulbs. Roots and leaves can also give rise to new plants. Thus, new individuals generate, for example, from the eyes of potatoes, the cloves of garlic bulbs, and the stolons of strawberry plants. See also Plant ; Plant Propagation .

Some plants produce special underground stems such as tubers, bulbs, and corms that enable them to reproduce asexually. Like all stems, these structures have buds, or nodes, from which new stems branch. Tubers are swollen, fleshy stems with several buds called eyes that produce new plants; an example of a tuber is the potato. Bulbs, such as those found in onions, lilies, hyacinths, and tulips, are short, wide, teardrop-shaped underground stems surrounded by scaly leaves. Corms, such as crocuses and gladioli, are similar, but lack the scaly leaves. Both bulbs and corms make clumps of new bulbs or corms, called offsets, which can be divided and buried in the soil to generate new plants. Irises and ferns produce rhizomes, fleshy stems that grow horizontally beneath the soil, with new plants developing from the tip of the rhizome and from each node on the stem. Stolons, specialized stems found in strawberries and many lawn grasses, are similar to rhizomes but are usually thinner and grow ...

Also called micropropagation, tissue culture is the production of plants under sterile laboratory conditions. A variety of tissue culture techniques are used to propagate plants. In one method, growers remove a tiny piece of leaf or stem from a plant and place it in a sterile test tube on a gel-like medium enriched with hormones and nutrients. A yellow-brown mass of cells called callus develops from the piece of plant. Small chunks of the callus are separated, and each piece is placed in a petri dish with a hormone and nutrient mix that stimulates the development of the callus pieces into plants. The young plants are removed from the petri dish and placed in pots with soil, or into the ground, where they grow to maturity. Tissue culture enables researchers and growers to rapidly generate numerous clones year-round in greenhouses. In nature, strawberry plants typically produce their fruits in summer. Commercially grown strawberries, however, are propagated throughout the year by ti...

In agamospermy, also known as apomixis, a seed develops directly from tissues of the ovule rather than from a fertilized egg. Depending on the species, a fruit may or may not be produced. The plants that develop by agamospermy are clones of the mother plant. Agamospermy occurs in nature in species such as dandelions and blackberries, enabling them to spread rapidly since they can bypass pollination and fertilization.

In grafting, a freshly cut section of stem with buds, called a scion, is joined to another plant called the stock. The upper stem of the stock is severed and the scion is joined to the lower stem. The scion is securely attached to the stock, and the tissues of the two plants grow into each other, forming a single plant. The scion produces the stems, leaves, and flowers on the new plant and the stock provides the root system. Grafting combines desirable qualities from one species, such as disease resistance or the ability to grow in waterlogged soils, with desirable qualities of another, such as the ability to produce high quality fruit. Grafting is often used to make fruit trees more vigorous and productive. Bud grafting is a form of grafting in which a single bud cut from a stem is grafted onto the stock. It can be carried out more rapidly than other forms of grafting and is used widely in the nursery industry to propagate hundreds or thousands of plants in a relatively short amo...

For many plant species, a leaf, section of stem, or piece of root cut from a plant and lightly covered in soil, peat moss, or another growth medium develops a new, independent plant by generating the missing parts. Stimulated by hormones called auxins, a partially buried leaf or piece of stem, for example, develops roots on the buried portion, and a piece of root forms stems and leaves above the soil. Cuttings and layering are widely used for perennial plants, plants that grow back from the same roots year after year. Commercially, cuttings are the most important source for perennials, such as new fruit trees; conifers, including pine and spruce; a variety of shrubs, roses and honeysuckle, for example; and many florist blooms. In layering, a new plant develops from a stem that is still attached to the parent plant. In nature, the stem simply arches over and spreads out on the ground. The parts of the stem that are in secure contact with the soil develop the roots, stems, and leaves o...

Asexual propagation is the production of new plants from the leaves, stems, or roots of a single parent plant. Asexual propagation, which does not require pollination or fertilization, is a rapid method of propagation. It ensures that all of the parent’s genetic material survives even if the parent dies, and it creates offspring, known as clones, with the same traits as the parent plant. Asexual propagation is advantageous when plants are well adapted to a particular environment. Several methods of asexual propagation occur in nature. They have been adapted for commercial use for rapid propagation and to obtain plants that are hard to grow from seeds. A. Cuttings and Layering B. Grafting C. Agamospermy D. Tissue Culture E. Propagation from Stems and Roots

Celery, common name for a biennial herb of the parsley family, a native of Europe but now widely grown throughout the world. The stalks, about 30 to 76 cm (about 12 to 30 in) high in cultivated varieties, are eaten, raw or cooked, as a vegetable or salad. When allowed to grow naturally, the stalks are greenish in color and slightly bitter in taste. They are often blanched during the last stages of their growth by preventing access of sunlight except to the leaves; this process removes the color and the bitter taste, but also some of the vitamins. If allowed to grow a second year, celery sends up flower stalks about 61 to 91 cm (about 24 to 36 in) tall with small white flowers in umbels. The dried fruit of celery is used as a condiment alone under the name of celery seed or ground and mixed with salt under the name of celery salt. Celery seed is also used in pharmacy as a sedative or to disguise the flavor of other drugs. Celery is subject to attack by several blights, by the tar...

Spinach, common name for an annual crop plant, of the goosefoot family, grown for its nutritious and savory leaves. Probably native to southwestern Asia, spinach was introduced to Europe by the 12th century. It became cultivated worldwide and received sudden popularity in the 1920s when nutritionists found it contained iron, vitamin A, and vitamin B2, or riboflavin. Two varieties of spinach are now grown. Wrinkled, or savoy, spinach can be packaged and shipped without wadding or spoiling and is marketed fresh. Smooth-leaved spinach can be easily washed and is marketed frozen or canned. Spinach leaves are picked from the immature plant when in the form of a rosette close to the ground. Because extended daylight and hot temperature cause the plant to bolt, or draw growth away from the leaves and into a tall, central flower stalk, spinach is best cultivated in cool climates during spring or fall, or in warm climates during winter. Most spinach in the United States is now produced i...

Orach, common name for a tall annual plant of the goosefoot family, native to Asia. Orach is also called garden orach and mountain spinach. It is cultivated in Europe and North America both as a foodstuff and as an ornamental. Orach grows to a height of 2 m (7 ft). Its furrowed stems bear soft, arrow-shaped leaves and small flowers in crowded clusters. The young shoots and leaves are eaten like spinach.  Scientific classification: Orach is a member of the family Chenopodiaceae. It is classified as Atriplex hortensis. 

Endive, also escarole, common name for a plant (see Composite Flowers ) having a curly, lettucelike head, with inner leaves that are used in salads. The inner leaves of the plant are sometimes blanched by enclosing the head of the endive in its outer leaves (which normally fall away) or by covering the entire plant with a special tube of paper. The long blanched shoot of chicory is called Belgian or French endive, or witloof. Scientific classification: Endive belongs to the family Asteraceae 

Dandelion, common name for stemless perennial or biennial herbs of the composite flower family, especially the common dandelion. The species has long taproots, rosettes of deeply incised lanceolate leaves, and flat flower heads containing bright yellow florets on hollow, stemlike stalks. The root of the common dandelion contains a substance used as a laxative; the root is also roasted and ground as a substitute or adulterant for coffee. The leaves are used for salad greens and potherbs, and the flowers are sometimes used for making wine. It is occasionally cultivated, especially in Europe, but is found chiefly as a persistent weed in all temperate regions. The red-seeded dandelion is similar to the common species, but is smaller, with reddish seeds and darker down. A Russian species has some importance as a source of latex. Scientific classification:  Dandelions belong to the family Asteraceae (formerly Compositae). The common dandelion is classified as Taraxacum officinal...

Catsear - Culinary Encyclopedia : " Catsear, also known as Flatweed, Hawkweed, Cat’s ear and False dandelion, is an aromatic plant with green colored lobed leaves,which are used in various culinary preparations. The plant, botanically known as Hypochaeris radicata or Hypochoeris radicata, has bright yellow flowers similar to dandelion, hence, the name “false dandelion”. The long leaves of this herb and flowers are used in the same manner as dandelion; however, the leaves of this herb are not as bitter as that of dandelion. Origin Catsear is a low lying perennial herb that is found growing in most lawns. It is native to Europe; however, it was also introduced into America, Australia, New Zealand and Japan.    Culinary Uses Catsear has many culinary uses, similar to that of dandelion - The leaves are usually blanched, steamed and cooked like any other leafy vegetable. This helps in removing the bitterness of the leaves, if any. Salads are made with the leaves...