Petrorhagia prolifera (L.) P.W. Ball & Heywood
Tunica prolifera, Kohlrauschia prolifera, Tunica
Petroragia, the Mother of Children
Petrorhagia velutina (Guss.) P.W. Ball & Heywood
Petrorhagia dubia (Raf.) G. Lopez & Romo
Tunica velutina, Kohlrauschia velutina, Tunica
Velvet Rockcress
A relatively small genus of annual plants native to the Mediterranean and Southern Europe. It is closely related to the genus Dianthus, and their flowers look very similar; for this reason, the two are often confused with one another.
The genus name derives from the Greek *petrá* + *ragás* > *régnumi*, since many species of the genus grow in rock crevices and stony soils. The specific epithet “proliferus” comes from “proles” + “fero” = “to bear children, offspring.” It is considered a fairly rare species, and it is recommended that it be classified as threatened in Central Europe.
The descriptive adjectives “velutinus-a” = velvety and “dubius-a” = doubtful, due to minor deviations from the genus’s basic characteristics.
The genus name Kohlrauschia is named in honor of Henriette Kohlrausch, a 19th-century German botanist. The genus’s older, now obsolete name, Tunica (meaning “tunic”), refers to the shape of the calyx lobes.
On Kythira, I have encountered these two species to date. Professor A. Giannitsaros also mentions the species Petroraghia graminea (Sm.) P.W. Ball & Heywood, which is closely related to the Petroraghia saxifraga L. Link. Kythira appears to be the southernmost location where this Greek endemic plant occurs.
