Plant of the Week
Blue Sage (Salvia azurea var. grandiflora)
By Christopher David Benda
Blue sage is a member of the Mint family (Lamiaceae). “Salvia” is a name that means “healer,” referring to this ancient name for a sage with medicinal properties. The species name “azurea” is Latin for “sky blue.” Blue sage is a common name that refers to several different plant species. The name “sage” refers to this plant being traditionally used as medicine for pain.
This plant grows up to five feet tall and has opposite leaves that are widely spaced along the stem. The flowers add a wonderful shade of blue in the autumn season when yellow and white flowers seem to dominate the landscape. They occur along a terminal spike with several flowers in each whorl. The flowers are blue and tubular, and the throat of the flower is white. The upper lip is hooded and is much shorter than the three-lobed lower lip, which serves as a landing pad for pollinators.
This fragrant, perennial plant is a favorite plant of pollinators. A variety of insects visit the flowers, but bumblebees and butterflies seem to be the most attracted to the flowers. Characteristic of the genus Saliva is the atypical pollination mechanism. Two stamens occur at the end of a stalk that acts as a lever, so when insects land on the flower, their backs become dipped in pollen. The unique structure of the stamens is believed to be the driving force in the diversity of this large genus. Also, the floral characteristics of this genus suggests it is a monophyletic group, but recent DNA analysis show it is actually a product of convergent evolution.
Once fertilized, the flowers produce shiny, ellipsoid nutlets. They are easy to propagate from seed. This is mainly a plant of western prairies and barrens. It primarily occurs in the heartland from Nebraska to Texas, and eastward to South Carolina. Many disjunct peripheral populations exist as well.