"salvia spathacea" is an evergreen perennial with flowering stems growing from a woody base, tall. when not flowering plants grow less than tall, forming clumps of sprawling foliage. each plant produces a single flowering stem which rarely branches. it spreads by rhizomes and can form colonies up to in diameter. like many species in the mint family it has very pronounced square stems, and the entire plant is covered with wavy glandular hairs.