Usually called simply 'common sage', this is a shrubby perennial plant growing to about 75 cm high. it has aromatic, downy, grey-green oval leaves and spires of pretty bluish-mauve flowers in spring and summer. It hails from Spain, the Balkans and North Africa. It needs a sunny position and very good drainage. It doesn't tend to last more than a season or two in Sydney, as it doesn't like our summer humidity.
However, by chance I found that cuttings will strike if grown in a glass of water on a windowsill (this happened in late summer - not sure if timing is important or not!). The rooted cuttings can then be potted on into potting mix and ultimately the plant put into the garden to take the place of an ageing specimen, rather than having to buy a new one every year. I have never had luck striking them in normal propagating mix. Sage is useful in many recipes; crispy fried sage leaves are a particular favourite of mine!
There are a couple of lovely cultivars: 'Tricolor' has green, cream and beetroot-red leaves, 'Icterina' has gold and green leaves and 'Purpurascens' has grey-green leaves that have a gorgeous purplish hue. In my experience, none of them are very successful in Sydney and they tend to die off fairly quickly. They grow best in cool inland areas.