Medicinal plants have been identified and used throughout human history. Toxic plants even have use in pharmaceutical development. Angiosperms (flowering plants) were the original source of most plant medicines. Some herbs and spices come from flowering plants.
Topics concerning medicinal plants include:
Worldwide more human beings gain their livelihood from agriculture than any other endeavor; the majority are self-employed subsistence farmers living in the tropics]citation needed[. While growing food for local consumption is the core of tropical agriculture, cash crops (normally crops grown for export) are also included in the definition.
When people discuss the tropics, it is normal to use generalized labels to group together similar tropical areas. Common terms would include the humid-tropics (rainforests); the arid-tropics (deserts and dry areas); or monsoon zones (those areas that have well defined wet/dry seasons and experience monsoons). Such labeling is very useful when discussing agriculture, because what works in one area of the world will normally work in a similar area somewhere else, even if that area is on the opposite side of the globe.
Ornamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as houseplants, for cut flowers and specimen display. The cultivation of these, called floriculture, forms a major branch of horticulture.
Most commonly ornamental garden plants are grown for the display of aesthetic features including: flowers, leaves, scent, overall foliage texture, fruit, stem and bark, and aesthetic form. In some cases, unusual features may be considered to be of interest, such as the prominent and rather vicious thorns of Rosa sericea and cacti. In all cases, their purpose is for the enjoyment of gardeners, visitors, and/or the public.
Fruit anatomy is the internal structure of fruit, the mature ovary or ovaries from one or more flowers. In fleshy fruits, the outer and often edible layer is the pericarp, which is the tissue that develops from the ovary wall of the flower and surrounds the seeds. Some edible "vegetables" such as the cucumber, squash, and tomatoes are actually botanical fruits.
In some seemingly pericarp fruits, the edible portion is not derived from the ovary. For example, in the fruit of the ackee tree, the edible portion is an aril; and in the pineapple several tissues from the flower and stem are involved.
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ingested by an organism and assimilated by the organism's cells in an effort to produce energy, maintain life, or stimulate growth.
Historically, people secured food through two methods: hunting and gathering, and agriculture. Today, most of the food energy consumed by the world population is supplied by the food industry.