The complex hierarchy of taxonomy of biological species includes many categories. Plant families are below the order (order) and above the genus. Their names are formed in accordance with the rules that are governed by international codes of the botanical nomenclature. The name of the plant family is formed by adding to the base of the name of the type genus the standard ending -aceae. So, for example, the name of the family Rosaceae (Rosaceae) is formed, which consists of the name of the genus “Rosa”, from which the base Ros- is taken and the ending -aceae is added. Derived ranks are sometimes used in the scientific classification: subfamily and superfamily.
Plant families in the modern sense arose at the beginning of the 20th century. For the first time, this category was introduced by the botanist from France, Pierre Magnol, as early as 1689. For many decades, it denoted groups of completely different character. This practice of using this name ceased only in 1906 with the adoption of the international rules of the botanical nomenclature. In accordance with the rules, this name began to mean everything that was previously called orders in Latin or families - in French.
Despite the variety of plants, it should be noted that some of them are more similar to each other, and some less. This similarity is determined by the affinity of these plants. It is related species that underlie the formation of families. It is estimated that more than 350 thousand species of various plants grow on our planet:
- Mossy: they have 1.3 thousand genera and 25 thousand species;
- ferns: there are 300 genera and 11 thousand species;
- horsetail: 1 genus and about 25 species;
- abundant: 4 genera and 1 thousand species;
- gymnosperms: 60 genera and 700 species;
- angiosperms (flowering): has more than 500 families, about 13 thousand genera and more than 250 thousand species.
There are plant families that most interest people in terms of their use in everyday life. Without such plants, a person’s life in general would be impossible, since many of them make up a significant part of his diet. One of the most common is the family of dicotyledonous plants. Characteristic features of such plants are: the presence of two cotyledons; the number of different flower elements in their overwhelming number is equal to or a multiple of 4 and 5; located annularly conducting fabric. The root system of these plants is predominantly pivotal. This family is represented by all life forms. Among the dicotyledonous plants, there are herbs, shrubs, and trees. This family comprises approximately 4/5 flowering plants on the planet.
Plants of the legume family belong to the class of dicotyledons. This is a very numerous species. The flowers of its representatives consist of 5 unequal petals, have an irregular shape, 10 stamens. Legume fruits are characteristically arranged. Their device is called the botanical term "bean." A common feature of the family is a one-membered ovary, which is not divided into lobes, and the fruit of all plants is multi-seeded, bivalve. The ripe fruit bursts at the seams of the valves, to which the seeds are attached.
Legumes account for about 6.6 thousand species and 200 genera. They are common throughout the planet. This family is divided into subfamilies: cesalpinium, mimosa, legumes. The latter account for the largest number of plants in the family. Some of them are the most important human food: beans, beans, lentils, peas, chickpeas, peanuts, soy. The fruits of these crops are high in vegetable protein, many minerals and vitamins. Many of them are used as valuable animal feed: clover, vetch, sainfoin, melilot, alfalfa. Herbaceous representatives of legumes, capable of extracting nitrogen from the atmosphere, are the main plants used in land reclamation.