Specific Epithet
/speh-SIF-ik EP-ih-thet/Also known as: species epithet, specific name
The specific epithet is the second half of a binomial name — the part that distinguishes one species from the others in its genus. In Quercus alba, Quercus is the genus and alba is the specific epithet. It is always written in lowercase and italicised, and it is never used on its own: alba alone is meaningless, because dozens of unrelated species share it. Epithets usually describe something about the plant — its colour (alba, white), its form (pendula, weeping), its origin (japonica, of Japan) or the person who found it (douglasii, for David Douglas). Learning the common epithets lets you read a great deal from a name you have never seen before.
Etymology
From Latin specificus (of a particular kind) + Greek epitheton (something added).
Example
“Once you know the specific epithet sempervirens means "always living", Sequoia sempervirens and Buxus sempervirens both tell you they are evergreen.”