As I was going for a sunset walk one evening I spotted a flower that I never thought I would get to see. I was so excited that I got up before sunrise to go photograph it the next morning. Meet the Dicerandra frutescens, aka Lake Placid Scrub Balm, one of the rarest plants at Archbold with one of the most amazing pollination stories.
Dicerandra is a strange plant. Of the thousands of insect species at Archbold, only one species can easily pollinate it, a bee fly called Exprosopa fasciata. This may seem like a problem, but it is actually to Dicerandra‘s advantage. In fact, Dicerandra has an incredible set of adaptations for excluding all other pollinators:
- Dicerandra hides its nectar at the base of the flower. Only insects with long tongues, like the bee fly, can reach it.
- When an insect lands on the lower petals, the flower bends at the base (see photo below), further blocking access to the nectar. Only powerful insects, like the bee fly, can unbend the flower by pushing on the upper petal (see photo above).
- Dicerandra also hides its pollen in its anthers (the pink globs sticking out). This prevents insects from stealing the pollen, such as small bees. It also prevents the pollen from drying out.
- When the bee fly reaches deep into the flower, its belly brushes against the anthers, causing pollen to pop onto the bee fly’s belly. When the bee fly visits another Dicerandra flower, this pollen gets brushed into a tube called the stigma, and fertilizes the plant!
This amazing plant only grows in the Florida scrub. Sadly, because of development and fire suppression, it now only exists at about 12 sites, all located in Highlands County, FL. It is listed as an endangered species by Florida and the US Government. Archbold’s Plant Ecology Program is doing lots of research to figure out how we can best protect and restore the Lake Placid Scrub Balm.
Deyrup, M. & Menges, E.S. 1997. Pollination Ecology of the rare scrub mint Dicerandra frutescens (Lamiaceae). Florida Scientist 60: 143-157.
Written and photographed by Evan Barrientos- Environmental Education Intern at Archbold Biological Station.