A Pollen Flora for Subtropical Florida - Suzanne Koptur (FIU)

THE PROBLEM

The Miami Herald makes daily reports of pollen counts, indicating the major pollen sources that might be a problem for people allergic to airborne pollen.  Frequently the sources listed are plants that do not occur in Miami, perhaps the result of allergists sending slides of pollen obtained from local air samplers to northern experts for determination.  These distant experts may misidentify pollen samples because of lack of familiarity with south Florida flora.  Allergists who are not aware of the local flora may test and treat their patients with extracts that do not even occur in this region, and do not use extracts of plants that may actually be causing allergic reactions.  Levels of threshold counts for pollen allergens have not been determined for many plant species other than grass and ragweed.  Cross-reactivity among different plant species can further complicate determination of the source of allergies.  A recent compendium used by allergists (Lawlor et al. 1995) lists only 14 types of tree, 7 grasses, and 8 other plants as “principal pollens”, only a fraction of the diversity that really occurs here.   Published reports on airborne pollen of Florida focus on central and northern Florida (Jelks 1989, 1996).  A list compiled by Dan Austin of Florida Atlantic University in 1991 lists allergenic extracts available from Miles Pharmaceutical; many of the extracts they supply to local allergists are from plants that do not occur in this area, and extracts are available of plants we do have that allergists do not routinely test for, yet may be causing problems.  Clearly, the local medical community needs better information on what pollens may be causing problems locally.

To address these shortcomings, I am developing an accurate and detailed database for pollen identification, a reference collection of pollen from native and exotic plants found in natural, suburban, and urban habitats of Dade County.  In the long term, we are documenting the flowering season for every plant species over multiple years, and determine the seasonality of every potential pollen allergen.  In the short term, I would like to make a book of photos of pollen from known sources to enable us to identify pollens we find in our pollination research on the bodies of insect visitors to flowers, on the stigmas (receptive female surfaces) of flowers, and also to help other people interested in pollen to identify pollens they find with aerosampling or other techniques.

This pollen is Pachystachys lutea