Cereals

Cereals, various species of the grass family, cultivated for their seed, which is used as food. The name is derived from Ceres, the Roman goddess of grains and agriculture. Although the cereals proper do not belong to any particular tribe of the grasses, the use of particular species as bread plants seems to have been determined chiefly by the superior size of the seed or by the ease of procuring it in sufficient quantity and of freeing it from its inedible covering. The most extensively cultivated grains are wheat, barley, rye, oats, rice, corn or maize, different kinds of millet, and the grain sorghums known as durra or guinea corn. These have all been cultivated since ancient times. Maize and wild rice are the only grains that originated in the Americas; the others were developed in Europe, Asia, and Africa.

Scientific classification: Cereals belong to the family Poaceae (formerly Gramineae). Wheat is classified in the genus Triticum, barley in the genus Hordeum, rye in the genus Secale, oats in the genus Avena, rice in the genus Oryza, and corn in the genus Zea. Millet is classified in the genera Setatia, Eleusine, Panicum, and Pennisetum. Durra or Guinea corn is classified in the genera Sorghum or Andropogon.

Almond

Almond, common name for a small tree of the rose family, and for the kernel of its fruit. The tree is characterized by the coarsely furrowed and wrinkled shell of the drupe and by the young leaves that have their sides folded along the central vein. It grows up to 9 m (30 ft) high. A native of western Asia, it now grows wild throughout southern Europe and is cultivated in the United States. The wood is hard, of reddish color, and is used by cabinetmakers. The almond is valued chiefly for its nut, which is an important article of commerce. Varieties are classified as either sweet or bitter. Sweet almonds contain a large quantity of a bland, fixed oil and emulsin, gum, and mucilage sugar; they have an agreeable taste and are nutritious. Bitter almonds contain the same substances and, in addition, a crystalline glucoside called amygdalin. The long almonds of Málaga, Spain, known as Jordan almonds, and the broad almonds of Valencia, Spain, are the most valued.

The dwarf almond tree, a low shrub, is similar to the common almond, with smaller fruit. It is common in the plains of Central Asia and is frequently planted as an ornamental shrub in England. Flowering almonds—shrubs or small trees—are cultivated extensively in the United States for their profusion of showy, white to rose blossoms.

Scientific classification: The almond belongs to the family Rosaceae. It is classified as Prunus amygdalus. The dwarf almond tree is classified as Amygdalus nana.

Plant

Plant, any member of the plant kingdom, comprising about 260,000 known species of mosses, liverworts, ferns, herbaceous and woody plants, bushes, vines, trees, and various other forms that mantle the Earth and are also found in its waters. Plants range in size and complexity from small, nonvascular mosses, which depend on direct contact with surface water, to giant sequoia trees, the largest living organisms, which can draw water and minerals through their vascular systems to elevations of more than 100 m (330 ft).

Only a tiny percentage of plant species are directly used by humans for food, shelter, fiber, and drugs. At the head of the list are rice, wheat, corn, legumes, cotton, conifers, and tobacco, on which whole economies and nations depend. Of even greater importance to humans are the indirect benefits reaped from the entire plant kingdom and its more than 1 billion years of carrying out photosynthesis. Plants have laid down the fossil fuels that provide power for industrial society, and throughout their long history plants have supplied sufficient oxygen to the atmosphere to support the evolution of higher animals. Today the world's biomass is composed overwhelmingly of plants, which not only underpin almost all food webs, but also modify climates and create and hold down soil, making what would otherwise be stony, sandy masses habitable for life.

learn more:

• Differentiation from other Kingdoms
• Plant Phyla
• Cell Structure and Function
• Tissue Systems
• Plant Organs
• Growth and differentiation
• Ecology

Poppy

Poppy, common name for a small family of herbaceous flowering plants occurring principally in the North Temperate Zone, and for its representative genus. The family contains about 23 genera and 210 species; many are important as ornamentals, and one species is the source of opium. Members of the family occupy varied habitats, but they are more common in open, well-drained areas. This preference helps explain why several members of the family, especially poppies, are bothersome weeds in cultivated fields. See also Bloodroot.

The representative genus contains about 50 species. The Oriental poppy is widely cultivated as an ornamental, and many color forms have been developed. The opium poppy produces several useful products. Its tiny seeds, produced in huge quantities in each of the plant's dry fruits, or capsules, are used in baking and produce an important drying oil. Opium is the dried sap, or latex, that is harvested from the capsules while they are still young. It contains many alkaloids, including morphine and codeine, that are useful in medicine. Heroin is synthesized from the morphine purified from the complex mixture of alkaloids in opium (see Drug Dependence).

The family shares its order with the fumitory family. This family contains about 16 genera and 400 species, also mostly found in the North Temperate Zone, with a few species located in mountainous regions of tropical Africa and South Africa. The most familiar member of the family is the bleeding heart; others are of minor ornamental importance.

The leaves are usually deeply divided and arranged in a rosette around the base of the short stem. The flowers have two to four sepals (outer floral whorls) and twice as many petals (inner floral whorls). The stamens (male floral organs) vary in number from six to many more, and the ovary (female floral organ) is superior (borne above and free from the other flower parts). The order characteristically has sap that is rich in alkaloids. The sap is clear and watery in the fumitory family, milky in the poppy family.

Scientific classification: Poppies make up the family Papaveraceae in the order Papaverales. The Oriental poppy is classified as Papaver orientale, and the opium poppy as Papaver somniferum. The family Fumariaceae is the only other family in the order Papaverales.

See picture of Opium Poppy and Golden Poppy.

Periwinkle

Periwinkle (plant), common name for herbs in a genus of the dogbane family. The leaves are opposite and evergreen. The flowers grow singly or in pairs from the axils of the leaves. The lesser periwinkle is a native of many parts of Europe, growing in woods and thickets. The greater periwinkle, which has much larger flowers and ovatocordate, or egg-shaped, leaves, is a native of southern Europe. Periwinkles are the source of alkaloids that are often used to treat cancer.

Scientific classification: Periwinkles make up the genus Vinca, of the family Apocynaceae. The lesser periwinkle is classified as Vinca minor and the greater periwinkle as Vinca major.