Topic: Chenopodiastrum hybridum syn of Chenopodium hybridum

I've been asked a question about the Chenopodiastrum hybridum and Chenopodium hybridum.  These appear to be listed as two separate species on the UKSI with no synonym link between them.

However, Stace 4 lists Chenopodiastrum hybridum as the now correct name with Chenopodium hybridum being a synonym.  This is also reflected in the International Plant Names Index.

Is there anyway that this could be updated in the UKSI and, if not, can any advice be given as to what name/TVK we should be using for this 'species'?

Many thanks