This perennial used to be known as Salvia rutilans and is the old-fashioned pineapple sage plant (ht 1m). It can be quite an aggressive plant as it tends to sucker. In a place where this is not a problem, you can let it go: otherwise it needs to be chopped back with a shovel every so often. It has pineapple-scented leaves and slim spikes of red flowers in autumn. A very pretty cultivar is 'Golden Delicious' (ht 1 to 1.5 m, pictured above) which has the same red flowers with beautiful golden foliage: a very striking combination. It looks good with yellow-variegated foliage and with dark purple leaves. It doesn't seem to spread quite as much as the plain-leaved species. The foliage is lime in part-shade and it still flowers quite well in this position. The leaves of pineapple sage can be made into a drink by steeping them in boiling water for five to ten minutes and adding a little honey. Cut this plant to the ground in late winter. It is sensitive to hard frost.
There is a lower-growing cultivar called 'Honey Melon' (ht 60-90 cm), also useful for hot-coloured border plantings; however, it can be quite invasive if it decides it likes your garden. It is sensitive to hard frosts.
Salvia elegans Purple Form is quite a distinct variation and has been given a separate entry.