Dear friends of @STEMsocial, it is known that plant biological diversity comprises an estimated 300,000 described species, ranging from aquatic unicellular photosynthetic organisms, to highly differentiated multicellular organisms adapted to terrestrial life, as a result of evolutionary processes between groups of plants, which have been classified by botanical methods, with the assignment of binary names over time.

Introduction

Plant classification systems have historically allowed organizing diversity and variability among plant organisms, starting from similarities and differences as a parameter and basic principle, this because they provide biological and artificial descriptors that allow differentiating in the field, the morphological aspects (shape) exhibited by plant species.

However, the main biological and artificial descriptors used in plant classification schemes take into account the formation of cell groupings, in order to distinguish between unicellular and multicellular plant organisms, and the presence of tissues specialized in the transport of water and food, in order to differentiate vascular from non-vascular plants.

On the other hand, besides the cellular groupings and the conduction tissues, the external structure of each plant species is another biological element, which allows to differentiate and therefore to classify the plants, when identifying individuals that present simple structures, without roots, stems and true leaves (group of plants identified like talofitas), included within this group to the fungi, algae and lichens, and vegetal species that present structures of greater complexity like roots, stem and true leaves commonly denominated cormofitas.

Fig. 2 Species of the genus Cosmos with bright fuchsia petals. Author: @lupafilotaxia.

Fig. 3 Species of the genus Cosmos with deep red petals. Author: @lupafilotaxia.

Conceptual Overview

Scientific name

The scientific name, of a plant is of relation binomial, that is to say, it is constituted by two parts; the first one is the gender, whose initial letter must be in capital letter, the second word corresponds to the specific epithet (dominant biological or artificial descriptor) written in small letters.

Fig. 4 The Poaceae family is considered the taxon with the least evolved attributes within the Magnoliophyta division. Author: @lupafilotaxia.

It is important to mention, that next to the scientific name of a plant should be written the initial or initials or full name of the author or authors, who first identified and described.

Systematic botany

Systematic botany is the branch of botany that deals with the identification, classification and nomenclature of plants. In this sense, within the objective of systematic botany are: 1) to order the enormous plant diversity, 2) to describe the species, assigning them names, 3) to present the possibilities in the form of identification keys in order to be able to classify them, and 4) to propose the possible phylogenetic relationships between groups of plants.

Fig. 5 Within the Magnoliophyta division, the taxon Magnoliopsidas presents a greater morphological diversity than Liliposid species. Author: @lupafilotaxia.

Taxonomy

Taxonomy, is a branch of systematic botany, which provides the principles (rules) and procedures to make a classification through models that reflect the degrees of identity of the plants, conditioned by the relationships.

Nomenclatura

The nomenclature, which creates the names in systematic botany, to designate plants or groups of plants (taxa). The creation of the names is regulated by a set of rules gathered in the International Code of Botanical Nomenclature.

Taxonomic categories

The biological plant classification, establishes groups of organisms similar to each other, which are located within a hierarchy, at the hierarchical level formed what is called category or range, within this system, the higher categories contain the lower ones, however, in increasing order the most common categories are; kingdom, division, class, order, family, genus and species.

The kingdom is a unitary concept, which contains several divisions, each of which may have one or several classes, each class may be formed by several orders, and each of these by one or several families, in turn the families are formed, each, by one or several genera, of which may have one or several species. Each category may have secondary categories, which in increasing sequence are: subkingdom, subdivisions, subclass, suborders, subfamilies, subgenera, subspecies.

In accordance with the international code of botanical nomenclature, adopted at the XII International Botanical Congress, held in Leningrad, Russia in 1975, it was possible to reconcile the terminations to be used in the taxonomic categories (see table 1).

Table. 1Taxonomic categories

Category	Termination	Example
Kingdom	-	Plantae
Division	phyta	Magnoliophyta
Class	opsida	Magnoliopsida
Order	ales	Magnoliales
Gender	Generic name	Annona
Species	Specific name	muricata

Auxiliary disciplines that support systematic botany

It is relevant to indicate, that the systematic evidences used in botany to establish the classifications and the phylogeny are obtained from a great variety of sources, this because all the parts of a plant in all the states of its development can provide biological characteristics, that must be gathered from data coming from other different disciplines, for that reason, the scope of origin of the biological characteristics is highly variable, and generally they are obtained by several lines of studies among these:

Cytology

In the case of cytology, as an auxiliary discipline of systematic botany, it provides mainly information about chromosomes, at the level of number, shape, size, centromere position, mating during meiosis, movement patterns, and other characteristics.

Fig. 6 Cells from Allium strain, cell mitosis line is indicated. Public domain image. Author: Vic-gompi, 2015/ CC BY-SA 4.0

Embryology

Embryology, as an auxiliary science of systematic botany, provides information on plant micro and megasporogenesis, the development of gametes, fertilization, the development of the endosperm, the embryo and the seed covers.

Fig. 7 Life cycle of fern specimens Public domain image. Author: Magnus C. / CC BY-SA 4.0

Comparative Anatomy

Comparative anatomy provides characteristics related to the internal structure of plants, and has been used for systematic purposes for over 150 years, and is useful both in practical identification, as well as in the determination of phylogenetic relationships.

Comparative Morphology

Systematic botany relies on comparative morphology to determine the similarities and differences between plants, based on the careful comparison of their external morphological structures and then deduce their degree of relationship.

Palynology

The study of pollen and spores, provides information on taxonomic characteristics of how the plant species includes about structure of the pollen wall, polarity, symmetry, shape and size of the grain.

Fig. 8 Tricapsular morphology of poppy flower pollen. Public domain image. Author: JWegscheider, 2020

Paleobotany

Paleobotany, as an area that studies the microfossils among these; pollen, leaves, stems or other parts of the plant, provides systematic botany with information about the composition and evolution of the flora of the past, data that serve to integrate the morphology compared with the ecological conditions of the past.

CONTRIBUTIONS OF THIS PUBLICATION

The scientific names of plant species, can in some way cause some discomfort at the time of identifying a species, this due to the deep-rooted habits for the vulgar designation that are usually used according to cultural knowledge, however, the principles and auxiliary disciplines used to assign scientific names, have their advantages not only for botanists, since there are universally recognized criteria for designating a name for each plant, these scientific names also facilitate the free transfer of ideas and information to professionals from other areas of knowledge.

BIBLIOGRAPHIC REFERENCES CONSULTED AND CITED:

[1] Sosef M., Degreef J., Engledow H., and Meerts P. Botanical classification and nomenclature - an introduction. Meise Botanic Garden, Belgium. 2020; ISBN: 9789492663207. Article: Online Access

[2] Smith J. The Scientific Names of Plants. Botanical Studies. 2017; 28. Article: Online Access

[3] Rapini A. Introduction to Botanical Taxonomy. Methods and Techniques in Ethnobiology and Ethnoecology. 2014; 123-139. Article: Online Access

[4] Hawksworth D. Terms used in Bionomenclature: The naming of organisms (and plant communities). Global Biodiversity Information Facility 2010. Article: Online Access

[5] Koeltz Scientific Books. International Code of Nomenclature for algae, fungi, and plants (Melbourne Code). Adopted by the Eighteenth International Botanical Congress Melbourne, Australia, July 2011. Article: Online Access

ATTENTION

Readers and followers

If you wish to read more scientific articles in English or Spanish, of excellent academic quality, do not hesitate to visit #STEMSocial and #STEM-espanol, communities that promote scientific content mainly in the areas of Science, Technology, Engineering and Mathematics.

RE: Closet Thoughts: Can We Give Some of These Away?