I checked one salvia, Salvia mexicana var.major. It seems to be a valid species and variety.
Most sources I found do NOT capitalize "mexicana" as a species name, though this journal was inconsistent about that. The journal agreed that the variety name "major" is not caitalized.
I found it cited in a technical journal called "Molecules", and it gave two references I did not check.
Title: "A New Languidulane Diterpenoid from Salvia mexicana var. mexicana"
Last paragraph of Section 1:
"Salvia Mexicana (Subgenus Calosphace),
comprises the varieties major, minor and mexicana [1,2];
which are endemic to the central states of Mexico."
Bernardo Antonio Frontana-Uribe, Martha Verónica Escárcega-Bobadilla, Rosa Estrada-Reyes,
José Antonio Morales-Serna, Manuel Salmón and Jorge Cárdenas
Journal: "Molecules" 2011, 16, 8866-8873; doi:10.3390/molecules16108866
References and Notes
1. Rodríguez-Hahn, L.; Cárdenas, J. Comparative chemotaxonomy in labiatae. Curr. Top.
Phytochem. 1999, 2, 91-102.
2. Epling, C. A Revision of Salvia Subgenus Salosphace. In Repertorium Specierum Novarum Regni
Vegetabilis; Verlag des Repertoriums: Berlin, Germany, 1939.