This page contains an explanation of some scientific and technical terms which are commonly encountered in wildlife and environment recording.
The glossary is intended to provide basic information, sometimes about fairly complex topics, and often links to more detailed information on external websites and publications. Whilst every effort has been made to ensure the accuracy of this information, information provided by third-party organisations may change or be removed without notice. Please contact contact Green Man Software Ltd with corrections or additions.
Please note that external links are provided for information only, and we cannot assume any responsibility or liability for materials available at linked sites, which are beyond our control.
| Term | Meaning |
|---|---|
| Apomictic species |
Plants that reproduce predominantly or exclusively by self-pollination or vegetative means. Offspring of apomictic species are clones of their parent: slight mutations in individuals can therefore lead to closely-related microspecies. |
| Casual (species) | A non-native species which occurs sporadically, and is not truly established in the UK (see naturalised species). |
| Form | An individual or group of individuals which exhibits minor differences in one or more characteristics from typical members of a species, which may or may not be heritable. Forms often relate to differences in colour, for example melanism. |
| Hybrid | Offspring from two different parent species. Parent species may be in the same genus (interspecific hybrids) or different genera (intergeneric hybrids). Hybrids are denoted by including an 'x' in scientific names. |
|
Microspecies (also known as sibling or cryptic species) |
Microspecies are visually very similar, however as they generally derive from uniparental reproduction (apomixis) they rarely exchange genetic material with each other. Microspecies are often indistinguishable except by experts in the field, and as a consequence grouped into "Species Aggregates" of closely-related populations. |
| Native (species) | A species which belongs naturally in the UK, having colonised by natural means. |
| Naturalised (species) |
An alien (non-native) species that has become established in the UK by accidental
or deliberate introduction. eg. Rabbit, Evening Primrose |
| Species |
A species is a recognisable group which:
A species may be distinguishable in a variety of ways, including shape, size, colour, behaviour and molecular or genetic characteristics (to name a few). Interbreeding (the flow of genetic material) with other species must be expected to remain small even if geographical or other potential isolating factors are removed. Recently recognition of non-darwinian gene flow (eg. apomixis) in populations has blurred the species concept somewhat. |
| Species aggregate | A group of closely related (generally apomictic) species that are difficult to distinguish visually. |
| Subspecies | Subspecies are taxonomic sub-divisions of a species, which usually arise as a consequence of geographical isolation within a species. Individuals belonging a particular subspecies differ in some way from other members of the species; however they continue to interbreed with other members of the species, and would merge into a single, population if geographical or other isolating factors were removed. |
| Variety | An individual or group of individuals which differs in one or more characteristics from typical members of a species, and which produces offspring with similar characteristics. It is used particularly to distinguish groups which exhibit ecological differences. |