The Catalogue of Life and The Plant List call S. guaranitica a synonym of S. coerulea. ITIS doesn't list either one of these species, and GRIN lists S. guaranitica as an accepted name with no synonyms, but its last update was in 2009, at which time the name was not verified. The site says NAME NOT VERIFIED, in bold face and all caps.
The CoL, on the other hand, cites 5 September 2014 as the date of its latest taxonomic scrutiny of this name as a mere synonym of S. coerulea.
I haven't found any taxonomic sources listing S. coerulea as a mere synonym of S. guaranitica. Wherever S. coerulea is listed, it's classified as an accepted species name.
All of these species names are subject to change, however, and our entries will change if and when the taxonomists change their minds.
