Q. I saw a group of plants with purple and white flowers near the Enid Haupt conservatory. Monarchs were swarming them! What are they?
The flyers are attracted to the color of Salvia leucantha, commonly called Mexican bush sage, is an evergreen shrubby perennial that is native to Central America and Mexico. In St. Louis, it is grown as an annual that typically rises 2-3’ tall in a single growing season. This sage is most noted for producing a very attractive late summer to frost bloom of showy bicolor flowers consisting of white corollas and longer-lasting funnel-form purple calyces. Flowers appear in dense, arching, terminal spikes (racemes to 10” long) that extend above the foliage. Flowers are attractive to butterflies and hummingbirds. Linear, lance-shaped, gray-green leaves (to 4” long) are borne in pairs on square stems. Foliage has a velvet-like texture, hence the sometimes used common name of velvet sage for this species.
Genus name comes from the Latin word salveo meaning to save or heal in reference to the purported medically curative properties attributed to some plants in the genus. Specific epithet means white-flowered.
Hope this is helpful.