Plant Names
Plants have common names and botanical names. The common names are sometimes really interesting and descriptive, but botanical names allow for accurate identification of a plant. The same common name can sometimes be used for different plants, and the same plant often has different common names in different places.
Botanical names must have at least two parts for accurate identification. This is known as the binomial system of plant naming, or nomenclature. Previously, long descriptions were used to identify individual plants. The binomial system condensed this to two parts, the genus and species.
The genus or generic name is the first part. A genus is a group of related plants belonging to the same family. The generic name is written with a capital to start with, and is in italics. The second part of the name is the species or specific epithet. A species is a group of related plants in a genus, and these can generally breed with each other. The species name doesn't have a capital, but is also in italics. Specific epithets are often really descriptive and can give you interesting information about the plants.
Latin is used for the botanical names as this was the language that was widely recognised and understood at the time. Very often the names are just 'Latinised', and Greek words are also incorporated.
Sempervivum arachnoideum
The genus is Sempervivum and the species is arachnoideum.
Sempervivum means that it is always alive, coming from the Latin 'semper', meaning always, and 'vivus' meaning alive.
Arachnoideum refers to the hairs on the rosette that look like a spider's web, coming from the Ancient Greek 'arachnion' meaning spider's web.
Sometimes there are further naturally occurring divisions of the species. A sub-species is a regionally or ecologically distinct variation in a species. It is usually abbreviated to subsp.
Allium senescens subsp. glaucum
Another division is varietas or variety, often abbreviated to var. This is a botanical variety and not the more general use of the word variety. A botanical variety is a natural variation in the plant, such as flower colour or form that is not related to its geographical position.
Sempervivum arachnoideum var. bryoides
This variety has smaller rosettes, and bryoides refers to the moss like appearance of the plant.
Cultivars are 'cultivated varieties'. This means that they are either bred or selected and maintained by people. The cultivar name is in inverted commas and is not written in italics. Sometimes the species name is still used, follwed by the cultivar, or you will sometimes find just the cultivar name follwing the genus.
Below left:
Sempervivum calcareum 'Greenii'
Below right:
Sempervivum 'Bronco'
Plant names are sometimes changed for various reasons and you may find the same plant under different names. It may be found that the plant had an earlier name recorded, and in this case, the first name should be used. Other reasons include name changes after research when a plant is thought to be more closely linked to a different species or genus. These are termed synonyms. An example is Hereoa glenensis which has a synonym of Bergeranthus glenensis. You may see this written as Hereroa glenensis (syn. Bergeranthus glenensis).
