This is a form of Salvia microphylla, probably Hot Lips from its foliage. It may be too small or cool to show its bicolored flowers.

Rich: You knew immediately that it is a microphylla, I'm sure from years of experience. Do you know of a good "textbook" that explains the differences between the kinds? Betsy's doesn't do this.

Not any books, unless you can read Latin descriptions of species in floras. The Manual of the Vascular Plants of Texas by Correll and Johnston would give a description of greggii.

Greggii has linear strap-like leaves with smooth edges (no teeth) and flowers two per axil; microphylla has heart-shaped leaves with teeth.

You might check out online herbaria like the ones at the Smithsonian and New York Botanical Garden.

Here is a link that might be useful: New York Botanical Garden

Thanks for the ideas and the link. Maybe I'll need to make up my own book.