A botanical name is a formal scientific name to each individual plant conforming to the International Code of Nomenclature for algae, fungi, and plants (ICN).
The purpose of a formal name is to have a single name that is accepted
and used worldwide for a particular plant or plant group.
For
example, the botanical name Sedum reflexum denotes a plant species
which is native to Northern, Central, and Southwestern Europe, where it
has accumulated various names in many languages. Later it has been
introduced worldwide, bringing it into contact with even more languages.
English names for this plant species include: Reflexed Stonecrop, Blue
Stonecrop, Jenny's Stonecrop and Prick-madam. The cultivar Sedum
reflexum 'Blue Spruce' is a blue-green-variegated horticultural selection of this species.
Botanical
names prevent people from confusing different species of plants, but
also indicate that different species are related. The genus (ex. Sedum)
is the unique name followed by the species (ex. reflexum). The first
letter of the genus is capitalized and the species in small letters.
Most of these names have their origin in Latin or Greek, are
combinations of languages or words, the name of somebody who is honored,
appearance or location.
Knowing what the Latin (and sometimes Greek) words mean can help
gardeners with their planning and maintenance chores. For instance, if
the available area is cramped, a plant with arboreum (tree-like) or
altissimum (very tall) in its name might not be the best choice.
Some names refer to special characteristics of the plants. Pubi, hirti,
villi, and barbi are all "combining forms" suggesting hairiness.
Combining forms are Latin roots with vowels added to facilitate
pronunciation. They frequently appear attached to more familiar
Latin-based words, like those for leaf and flower. Hirtifolia would mean
hairy leaved. Barbiflora would mean bearded flower.
It is getting really interesting when we look at cultivars of plants
like Sedum reflexum 'Blue Spruce'. 'Blue Spruce' is a
blue-green-variegated selection of this species. Variegations of plants
can be caused by environmental conditions (air quality, sun light,
nutrients, water supply etc.) or by targeted human influence like
propagating only the plant with certain properties, propagating plants
with “defects” or Gen manipulation (like most of our food plants,
ornamental plants or turf grasses).
Vegetation
for Green Roofs should be identified, specified and communicated by
their botanical name to avoid confusion. The names of the plants must be
written correctly according the International Code of Nomenclature and
professionals don’t refer to the “Latin” name of a plant – they refer to
the botanical, horticultural or formal scientific name of plants.
Recommended readings (only English):
•• Mabberley's Plant-book: A Portable Dictionary of Plants, their Classifications, and Uses [Hardcover]
An Aid to the International Code of Botanical Nomenclature