ruthen-
combining form 
or ruthenio- or rutheno-
Etymology: International Scientific Vocabulary, from New Latin ruthenium 
 : ruthenium : ruthenious 
< ruthenammines >
< rutheniopalladium >
< ruthenonitrite >
or ruthenio- or rutheno-
< ruthenammines >
< rutheniopalladium >
< ruthenonitrite >