Plant taxonomy is the science that finds, identifies, describes, classifies, and names

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae excl ...

s. It is one of the main branches of

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

(the science that finds, describes, classifies, and names living things). Plant taxonomy is closely allied to

plant systematics The history of plant systematics—the biological classification of plants—stretches from the work of ancient Greek to modern evolutionary biologists. As a field of science, plant systematics came into being only slowly, early plant lo ...

, and there is no sharp boundary between the two. In practice, "plant systematics" involves relationships between plants and their

evolution Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

, especially at the higher levels, whereas "plant taxonomy" deals with the actual handling of plant

specimen Specimen may refer to: Science and technology * Sample (material), a limited quantity of something which is intended to be similar to and represent a larger amount * Biological specimen or biospecimen, an organic specimen held by a biorepository f ...

s. The precise relationship between taxonomy and systematics, however, has changed along with the goals and methods employed. Plant taxonomy is well known for being turbulent, and traditionally not having any close agreement on circumscription and placement of

taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...

. See the

list of systems of plant taxonomy This list of systems of plant taxonomy presents "taxonomic systems" used in plant classification. A wiktionary:taxonomic system, taxonomic system is a coherent whole of alpha taxonomy, taxonomic judgments on circumscription (taxonomy), circumscr ...

Background

Classification systems serve the purpose of grouping organisms by characteristics common to each group. Plants are distinguished from animals by various traits: they have

cell walls A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mech ...

made of

cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wa ...

polyploidy Polyploidy is a condition in which the biological cell, cells of an organism have more than one pair of (Homologous chromosome, homologous) chromosomes. Most species whose cells have Cell nucleus, nuclei (eukaryotes) are diploid, meaning they ha ...

, and they exhibit sedentary growth. Where animals have to eat organic molecules, plants are able to change energy from light into organic energy by the process of

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in ...

. The basic unit of classification is

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

, a group able to breed amongst themselves and bearing mutual resemblance, a broader classification is the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

. Several genera make up a family, and several families an order.

''Plantae'', the Plant Kingdom

The plant kingdom is divided according to the following:

Identification, classification and description of plants

Three goals of plant taxonomy are the identification, classification and description of plants. The distinction between these three goals is important and often overlooked.

Plant identification In biology, determination is the process of matching a specimen of an organism to a known taxon, for example identifying a plant. The term is also used in cellular biology, where it means the act of the differentiation of stem cells becoming fix ...

is a determination of the identity of an unknown plant by comparison with previously collected specimens or with the aid of books or identification manuals. The process of identification connects the specimen with a published name. Once a plant specimen has been identified, its name and properties are known. Plant classification is the placing of known plants into groups or categories to show some relationship.

Scientific classification Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

follows a system of rules that standardizes the results, and groups successive categories into a

hierarchy A hierarchy (from Greek: , from , 'president of sacred rites') is an arrangement of items (objects, names, values, categories, etc.) that are represented as being "above", "below", or "at the same level as" one another. Hierarchy is an important ...

. For example, the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

to which the lilies belong is classified as follows: * Kingdom:

Plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae excl ...

ae * Division:

Magnoliophyta Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants t ...

* Class:

Liliopsida Liliopsida Batsch (synonym: Liliatae) is a botanical name for the class containing the family Liliaceae (or Lily Family). It is considered synonymous (or nearly synonymous) with the name monocotyledon. Publication of the name is credited to Scopol ...

* Order:

Liliales Liliales is an order of monocotyledonous flowering plants in the Angiosperm Phylogeny Group and Angiosperm Phylogeny Web system, within the lilioid monocots. This order of necessity includes the family Liliaceae. The APG III system (2009) places ...

* Family:

Liliaceae The lily family, Liliaceae, consists of about 15 genera and 610 species of flowering plants within the order Liliales. They are monocotyledonous, perennial, herbaceous, often bulbous geophytes. Plants in this family have evolved with a fair ...

The classification of plants results in an organized system for the naming and cataloging of future specimens, and ideally reflects scientific ideas about inter-relationships between plants. The set of rules and recommendations for formal botanical nomenclature, including plants, is governed by the

International Code of Nomenclature for algae, fungi, and plants The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "trad ...

abbreviated as ICN. Plant description is a formal description of a newly discovered

, usually in the form of a scientific paper using ICN guidelines. The names of these plants are then registered on the International Plant Names Index along with all other validly published names.

Classification systems

These include; *

APG system The APG system (Angiosperm Phylogeny Group system) of plant classification is the first version of a modern, mostly molecular-based, system of plant taxonomy. Published in 1998 by the Angiosperm Phylogeny Group, it was replaced by the improved A ...

(''angiosperm phylogeny group'') **

APG II system The APG II system (Angiosperm Phylogeny Group II system) of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Gr ...

(''angiosperm phylogeny group II'') **

APG III system The APG III system of flowering plant classification is the third version of a modern, mostly molecular-based, system of plant taxonomy being developed by the Angiosperm Phylogeny Group (APG). Published in 2009, it was superseded in 2016 by a fu ...

(''angiosperm phylogeny group III'') **

APG IV system The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was published ...

(''angiosperm phylogeny group IV'') *

Bessey system A system of plant taxonomy, the Bessey system was published by Charles Bessey in 1915. Description Bessey based his system on the tradition of de Candolle, Bentham and Hooker and Hallier. He was also influenced by Darwin and Wallace. He taug ...

(''a system of plant taxonomy'') *

Cronquist system The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in a series of monographs and texts, including ''The Evolution and Classification of Flowering Plants'' (1968; 2nd edition, 1988) ...

(''taxonomic classification of flowering plants'') *

Melchior system The Melchior system, "a reference in all taxonomic courses", is a classification system detailing the taxonomic system of the Angiospermae according to A. Engler's ''Syllabus der Pflanzenfamilien'' (1964), also known as "modified or updated" Eng ...

Online databases

* Ecocrop * EPPO Code * GRIN See Online botany databases

References

External links

Plant systematics

Tracking Plant Taxonomy Updates discussion group
{{Taxonomy of...