Swedish naturalist Linnaeus (1707-1778) system has played a huge role in the further development of the taxonomy and botany in general. Linnaeus laid

Linnaeus classification [system, taxonomy]

Swedish naturalist Linnaeus (1707-1778) system has played a huge role in the further development of the taxonomy and botany in general. Linnaeus laid the foundation of the system structure of the flowers, attaching great importance to the number of members, mostly of stamens. Linnaeus divided the plant world into 2 groups — flowering and non-flowering (without stamens and pistils). Linnaeus considered that stamens and pistils were genitals of flower and called flowering plants as the phanerogams; other plants that did not have stamens and pistils, he called cryptogams as their fertilization process was unknown in the days of Linnaeus. Phanerogams were divided by Linnaeus in 23 class, 24th class was a cryptogams plants.

The first classes of the system were based on the number of stamens:

  • 1st class Monandria — plants with one stamen;
  • 2nd class Diandria — plant with two stamens;
  • classes 3, 4, 5, 6th — plants with 3, 4, 5, 6 stamens, etc...

Besides the number of stamens, Linnaeus took into account unisexuality and bisexuality of flowers, the phenomenon of members intergrowth and so on. The Linnaean system of plants, which appeared for the first time in 1735 in his essay “The system of nature”, had such a success so this book withstood 12 editions from 1735 to 1868.

Linnaeus' system put in order the chaotic state of systematics and extremely simplified acquaintance of every literate person with botany. This caused a great interest in the study and description of the plants.

Linnaeus' system is artificial. To show its artificiality is sufficient to consider two examples. Such a natural group of plants like Poaceae, according to Linnaeus, must be scattered over different classes. Most Poaceae with 3 stamens, get into his 3rd grade; but there are grains having two stamens (e.g. Anthoxanthum odoratum — occurring everywhere on upland meadows), and they should be assigned to the 2nd class. On the other hand, in the same class as Poaceae will be widely separated families, such as willow (Salicaceae). Many species of willow (Salix) have 3 stamens.

Linnaeus' great merit is that he has ordered a system of organisms’ notation (both plants and animals), first proposed by A. Bachmann (1652-1723) in 1680, coined the so-called binary nomenclature, which literally means — a double name. Before Linnaeus species were differed mainly by descriptions, composed by botanists upon discover. Name given to the plant was sought to cover all the features that distinguish it from the others, so they were consisted of the whole description, sometimes in 1.5-2 pages.

Linnaeus introduced a new principle in biological nomenclature. He offered to name plants in two words. The first name should be a noun and characterize the race, the second — an adjective and reflect the most characteristic features of this type. In addition, Linnaeus proposed the plant names to be in Latin. Thereby the confusion that reigned in the names of the plants in botanists of various countries was avoided. Latin as neutral and dead language was the most convenient for this purpose. After names of the plants, name abbreviation of the author who described the plant, should be placed. Descriptions of the newly discovered plants (diagnosis) should be prepared in Latin and printed in some publications coming out in each country. As the starting point (for establishing priority) has been accepted edition, undertaken by Linnaeus — “Types of plants” (“Species plantarum”), which has appeared in 1753. Here are some examples to clarify the naming method with binary plant nomenclature.

The currant plant is found in several types: red currants, black currants. As ornamental shrub is commonly bred the golden currant. They all belong to the genus “Ribes” and have slight differences that are reflected in the adjective accompanying the noun — Ribes. Here we have 3 types of the same genus — Ribes: black currant — Ribes nigrum L., red currants — Ribes rubrum L., golden currant — Ribes aureum Pursch. Taken from http://worldofschool.org

Genus of currants in Latin is called Ribes (nigrum — black, rubrum — Red, aureum — golden).

Linnaeus was a typical representative of his era, and it affected his philosophical views. He was a proponent of permanence, immutability of species. Nature is powerless to create new species, said Linnaeus. There are as much species as Almighty God created. According to Linnaeus, species divide into varieties and are grouped in genera. “Every genus is natural, as it was created at the beginning of the world.” But Linnaeus was clearly aware of the failure of an artificial system and by the end of life created a natural system that contained 65 orders, most of which coincides with currently accepted natural plant groups. His contemporaries did not appreciate the importance of Linnaeus attempt, and his natural system remained not understood. On the contrary, his artificial system of plants acquired great fame.

Questions:
  • What did Carl Linnaeus do?

  • What was Carl Linnaeus famous for?

  • Which evidence did Carl Linnaeus use to classify organisms?