Haworthia retusa var. nigra, formerly known as Haworthia mutica var. nigra, is a small succulent that forms rosettes of fleshy, light…
Meaning: Shining black
Derivation: Feminine form of the Latin adjective "niger."
Whereas the generic name must be unique, there are often two or more genera with the same specific epithet. The same epithet can also be used within a species for subspecies, varieties, and forms.
Here is a full list of succulents with this epithet. Click on the photo or the name of the plant for which you wish to see further information.