More Beautiful with Brooksville Bellflower

In April, final tallies were made of the number of Brooksville Bellflower observed in each population in spring 2021. Brooksville bellflower, Campanula robinsiae, is a short-lived annual, germinating in early spring, flowering and seeding by the end of March, and dying back in April. Each year since 1995, Bok Tower Gardens has been performing bellflower counts in each of the remaining populations in order to keep track of the species. Over the years, the number of plants has greatly declined, primarily because the largest population, which once held over a million plants, was destroyed by development. Since then, total annual plant counts have ranged from 8,000 down to zero.

The presence and number of plants each year are highly dependent on winter rainfall and the quality of the habitat. Typically, winter rains fill the ponds and raise the water levels along the banks. By mid-February, the water level has receded, leaving them exposed, wet muck that is ideal for the germination of the bellflower. If winter rainfall causes the pond margins to be too dry or too flooded during the critical germination period in mid-February to early March, no germination may occur for that year.

Even with ideal winter rainfall, poor quality habitat can prevent germination. Historically, deer, rabbits, and other grazing animals would frequent the pond as a water source and graze on the vegetation, maintaining open areas of soil or muck, and preventing overgrowth of tree and shrub seedlings and grasses. This would allow low ground cover herbs, including the bellflower, the ideal habitat.

Although winter rainfall is out of our control, in recent years, the Rare Plant Conservation Program has been working with landowners to improve habitat for the bellflower, and this has helped increase plant numbers.

2021 saw the second-highest number of plants over the past seven years, with 4,382 plants across three populations. We continue to work with landowners and project partners to study this species and to work to increase annual plant numbers in the future.

The post was written by the Rare Plant Conservation Program team at Bok Tower Gardens.