There are four, no five types of sage. Six, you say? Seven?
Sages are Salvia spp., as the Artemisia spp. are better called artemisias. Or perhaps mugworts.
First, there's the scented anti-inflammatory salvias that are good for the lungs. The type example of that is garden sage (Salvia officinalis), but you can use these as well:
- the various clary sages: sticky clary (Salvia glutinosa), meadow clary (Salvia pratensis), Balkan clary (Salvia sylvestris), verbena sage (Salvia verbenaca), whorled clary (Salvia verticillata), and real clary sage (Salvia sclarea). I've tried to grow real clary a few times, but it's a biennial and dies during our winters: it has never gotten to the flowering stage in my garden. I rarely see it, and a visit to Kew gardens last September had me going hmmm: I had remembered its scent as being nice, not catpissy.
I'm growing a very nice perennial clary-sage type with small off-white flowers, but I don't know which Salvia it is.
- autumn sage (Salvia greggii), with its exquisite scent - I do hope it'll survive the winter in my garden (... it didn't.).
- Cleveland sage (Salvia clevelandii).
There are others: try any of them as an anti-inflammatory lung herb if they're scented, except if they're pineapple sage.
There's the pretty sages with no scent. I don't know if they can be used for anything: blood sage (Salvia coccinea), scarlet sage (Salvia splendens), mealy-cup sage (Salvia farinacea), and many more.
There's the chia sages, used for their mucilaginous seeds: chia sage (Salvia columbariae), the gorgeous gentian sage (Salvia patens), named for the color more than the taste or scent, and Salvia polystachya, another chia. There are more of these, too.
There's divining sage, Salvia divinorum. I haven't used it, nor am I planning to.
The Chinese use the root of Chinese sage (Salvia miltiorrhiza) for something or other, quite unlike other sages; though I don't know how many westerners have used the roots of their sages. It's possible that we'd get the same effect from the roots of one or the other local salvia, and just haven't been using them.
Pineapple sage (Salvia elegans) is herbally more like the scented geraniums than the sages: use the scent as a mood lifter (rub a leaf and inhale the scent), and use the leaf to make tasty teas.
Whitesage (Salvia apiana) is simply divine. I use the dried leaf for smudging and the tincture as a perfume, and I use whitesage as a very strong garden sage -- but only when I have no other garden-sage-type salvias left in my cupboard.
That's seven. Have I forgotten any?