Unknown. The plant-name is borrowed from or well possibly cognate to semantically congruent Aramaic רִיתְמָא / רִתְמָא (riṯmā), רֹותְמָא / רֹתְמָא (rōṯmā), Hebrew רֹותֶם / רֹתֶם (rōṯem), the rest is likely denominal.
Oefen met het spreken en memoriseren van " رتم " en vele andere woorden en zinnen in Arabic .