As I was wandering Archbold Biological Station one sunset, I could hardly believe my eyes when I spotted these delicate flowers in the fading light. I was so excited that I got up before sunrise the next morning to go back for photos. It’s probably one of the rarest species I’ve ever seen.
Meet the Lake Placid Scrub Balm (Dicerandra frutescens), one of Florida’s most endangered plants 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’s actually to Dicerandra’s advantage. In fact, Dicerandra has an incredible set of adaptations for excluding all other pollinators:
- Nectar is stored 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), preventing most insects from reaching the nectar. Only powerful insects, like the bee fly, can unbend the flower by pushing on the upper petal (see photo above).
- Pollen is hidden inside the 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 is found only 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.
Let’s hope that land preservation and proper management continue to keep this wonderful plant in existence.
Deyrup, M. & Menges, E.S. 1997. Pollination Ecology of the rare scrub mint Dicerandra frutescens (Lamiaceae). Florida Scientist 60: 143-157.