Wild Blue Sage
Salvia azurea grandiflora
Mint family (Lamiaceae)
Description: This native perennial plant is 2½-5' tall; it is unbranched, or with a few small stems near the inflorescence. The central stem is ridged and slightly pubescent. The opposite leaves are greyish green, narrowly lanceolate, with serrated or dentate margins toward their tips. They are about 3-5" long and ¾" wide, becoming linear and shorter near the inflorescence. The foliage exudes a sage scent and has a sage taste.
There is one or more whorled spikes of flowers toward the apex of the plant that are up to 1' long. The corolla of these flowers ranges in color from pale blue to deep dark blue, usually with a lighter-colored throat. The corolla is short and tubular, dividing into a small upper lobe and a large lower lobe that functions as a landing pad for visiting insects. The tubular calyx is dull green, longitudinally ridged, pubescent, and bluntly toothed. Each flower is about ¾" long from top to bottom. The blooming period occurs during the late summer and fall, and lasts about 1-2 months. There is no floral scent. Only a few flowers are in bloom at the same time. The root system consists of a large central taproot, from which several stems may be produced.
Cultivation: The preference is full sun and dry, well-drained conditions. Different kinds of soil are acceptable, including those that contain significant amounts of loam, clay, or gravel. A high pH is tolerated. The seed germinates readily, often producing flowering plants during the first year. This is a surprisingly easy plant to grow, with few problems from disease. If the soil is too moist and fertile, or sunlight is insufficient, plants may become spindly and flop over while blooming later in the year.
Habitat & Range: Wild Blue Sage is a rare plant in Illinois with state-listed 'threatened' status. It has been reported from only a few scattered counties, primarily in central and southern Illinois (see Distribution Map). In the past, authorities have assumed that this plant was adventive from the west, but there is a growing tendency to regard it as indigenous to the state. Habitats include dry, upland areas of black soil prairies, gravel prairies, limestone glades, roadsides, and miscellaneous waste areas. This plant would likely thrive in dolomite prairies and hill prairies, although it has not been observed in such areas.
Faunal Associations: Long-tongued bees visit the flowers for nectar, especially bumblebees. Halictid bees occasionally collect pollen, but they are non-pollinating. Less often, butterflies and skippers may visit the flowers for nectar, including Epargyreus clarus (Silver-Spotted Skipper). The caterpillars of the moth Sphinx eremitus (Hermit Sphinx) may feed on the foliage. Mammalian herbivores usually avoid this plant as a food source – apparently they dislike the sage scent, or perhaps the scent is associated with indigestion from chemicals that disrupt bacterial populations in their digestive tracts.
Photographic Location: The photographs of the flowering plant and flower close-up were taken at Meadowbrook Park, Urbana, Illinois, while the photograph of the leaf was taken at the wildflower garden of the webmaster in the same city and state.
Comments: This is a wonderful plant with attractive blue flowers – a pleasant alternative to the preponderance of goldenrods and asters during the fall. It can be confused with no other plant within the state. Wild Blue Sage is more common in states that lie west of the Mississippi River, such as Nebraska and Missouri. In Illinois, only small remnant populations exist. A different variety occurs in some southeastern states, Salvia azurea azurea, which has less showy flowers. In the past, the scientific name for Salvia azurea grandiflora was Salvia pitcheri, and it is still referred to as Pitcher's Sage by some authorities.