For example, the weeping form of European beech is called Fagus sylvatica forma pendula. This leaves us with variety or subspecies. A variety of a plant usually differs from the species in where it grows. For example, sugar maples, Acer saccharum, usually grow from Canada to Georgia and as far west as Minnesota. However, the variety called nigrum grows in Iowa.
Variety is abbreviated var. and subspecies is abbreviated subsp. or ssp.
The Offspring of Mixed Plant Marriages When two different species of plant are crossed, sexually producing offspring, the botanical name of the new plant is written as a formula. An example of this is Laburnum x watereri. One of this plants' parents is Laburnum alpinum and the other is Laburnum anagyroides. Most hybrid plants are the result of controlled breading between two related species, both plants have the same genus. However, occasionally two plants from different genera are bread.