Botanical Nomenclature

1. Botanical Nomenclature • Plants may have many common names • Plants have only one scientific name • Scientific names are universally accepted

2. Binomial System of Classification • Invented by the Swedish naturalist Linnaeus in the year 1753 • The genus comes first and is always capitalized and italicized • The specific epithet comes after the genus and is always lower case and italicized

3. The Species • The genus and specific epithet together form the “binomial” that identifies a species • Example: Cercis canadensis Eastern Redbud • A group of individual plants that have a common set of identifiable characteristics that are inheritable • Species come “true-to-type” from seed

4. The Variety • A group of plants subordinate to the species; differing from the species in one or more inheritable characteristics • Varieties come “true-to-type” from seed • Written in lower case and italicized • Two acceptable formats: Cercis canadensis var. alba or Cercis canadensis alba

5. The Variety Cercis canadensis Cercis canadensis var. alba

6. The Cultivar • In ornamental horticulture cultivar characteristics are, generally speaking, not inheritable • Cultivars, generally speaking, do not come “true-to-type” from seed • Cultivar names are always capitalized and written in single quotations • Example: Cercis canadensis ‘Forest Pansy’ has maroon leaves that fade to green

7. The Cultivar • A single species may have many cultivars Juniperus horizontalis ‘Blue Chip’ Juniperus horizontalis ‘Plumosa’ Juniperus horizontalis ‘Hughes’ etc. • It is possible to have a cultivar of a variety Gleditsia triacanthos inermis ‘Skyline’ or Cornus florida rubra ‘Cherokee Chief’

8. Gleditsiatriacanthos

9. Gleditsiatriacanthosvar. inermis Gleditsiatriacanthosvar. inermis‘Skyline’

10. The End