Recognition, Identification and Names Spring 2014

Recognition relies upon previous experience with the organism. You “know” it is this, because you’ve seen it before, and have learned the name from some authority. The process of identification relies upon an analytical review of the characters observed, and following a logical order of inclusion and exclusion, to finally arrive at the name through the use of identification keys, for example, or some other resource. Confirmation of the name is done through comparison with a known “standard” (e.g., checking the specimen against previously identified specimens in a reference collection, the herbarium), or consulting with an authority who has much experience with the plant group, or checking a published treatment of the plant diversity of your region (flora) or a photographic atlas or web resource for that group of plants. Recognition versus Identification

Elements of Understanding Biological Diversity Description of Diversity Classification of Diversity Naming of Diversity Identification of Diversity

Elements of Understanding Biological Diversity Description: requires observation and measurement of characters and their states and synthesis of this information Classification: requires hierarchical organization of taxa based on evolutionary relationships Naming: requires following nomenclatural conventions and enables communication Identification: requires tools such as keys that are based on previous description, classification, and naming of taxa

Description Provides some basic identifiable set of characteristics to associate with the organism. Can be as general or as detailed as practicality dictates. Needs to contain enough data to provide adequate discrimination between similar organisms. Needs terminology. Descriptions are linked with a name when there is consistency in the set of observed characters for a given organism.

Fig. 16.2

Description of Bambusa from the Flora of China

Classification Classification provides ORDER to the group of entities. Relies on observations, many definable and comparable characters, and an ability to discern them. Completely effective classifications can be artificial, that is, not necessarily reflecting evolutionary relationships: i.e., trees vs. shrubs vs. herbs. But modern classifications are based on evolutionary history (phylogeny) because this provides predictive power. Biological classifications are hierarchical.

Hierarchical (nested) categories and phylogeny PHYLUM CLASS ORDER FAMILY GENUS TIME

…have only RELATIVE meaning, not absolute meaning! …are artificially created to accommodate different hierarchical levels of organization. …rely on inclusiveness of various shared characteristics that all members of the group should possess. …are subject to modification as data accumulate! Taxonomic Ranks…

Naming and Nomenclature We need names to communicate about plants with others. Organized system of names enables fitting the plant into an accepted scheme. Following formal naming rules is nomenclature (International Code of Nomenclature for algae, fungi & plants) The system must allow for changes as new information (and other species) are discovered. Will discuss the rules of nomenclature in more detail later in the semester.

Names of taxonomic ranks: standardized endings* Kingdom Chlorobionta (Viridiplantae) Phylum/Division: Magnoliophyta (Angiospermae) Class: Liliopsida Order: Poales Family: Poaceae Subfamily: Bambusoideae *These are for plants and fungi; there are different ones for animals.

Names of taxonomic ranks: standardized endings* Kingdom Chlorobionta (Viridiplantae) Phylum/Division: Magnoliophyta (Angiospermae) Class: Liliopsida Order: Poales Family: Poaceae Subfamily: Bambusoideae *These are for plants and fungi; there are different ones for animals.

Name of a bamboo Class: Liliopsida (Monocots) Order: Poales Family: Poaceae Subfamily: Bambusoideae Genus: Chusquea Kunth Species: Chusquea pohlii L. G. Clark

Genus names Do not have standardized endings Must be italicized Often the name of the author follows the genus name Chusquea Kunth

Species names Are always a binomial (genus name or epithet + species name or epithet) Must be italicized Often appear with the name of the author(s) of the species Chusquea pohlii L. G. Clark

Classification and Names Ideally, classification should reflect phylogeny And names should reflect the classification and phylogeny

Identification Relies on previous description, classification, and naming of taxa Keys are the primary means of plant identification Keys can take different forms, but the most common is still the dichotomous key

Dichotomous keys Consists of a series of two contrasting statements (each called a lead); each pair of statements is called a couplet Should be able to eliminate one set of possible identifications at each couplet Rules for constructing dichotomous keys are found on pp of the lab manual

Fig. 15.1

Interactive keys