Bonjour,
Merci beaucoup Jean-Paul pour ces informations 😉
Après la consultation de ces remarquables études sur la section Deliciosi, Lactarius sanguineovirescens Fillion (1989) est tout simplement synonyme de Lactarius semisanguifluus R. Heim & Leclair (1950).
PS: L'écriture correcte est sanguineovirescens, sans trait d'union.
"Art 60.9. The use of a hyphen in a compound epithet is treated as an error to be corrected by deletion of the hyphen. A hyphen is permitted only when the epithet is formed of words that usually stand independently, or when the letters before and after the hyphen are the same".