ibclogo XVI International Botanical Congess


Abstract Number: 2273
Poster No. = 672


Trap function in Utricularia purpurea Walter


J. H. Richards (Dept. of Biological Sciences, Florida International University, Miami, FL 33199, USA)


The genus Utricularia occurs world-wide in moist, oligotrophic habitats. These rootless plants are considered to be carnivorous. I examined trap morphology and function in U. purpurea, a common aquatic in south Florida, USA. U. purpurea has 5 (4-6) trapping processes per node and 64 + 31 traps per process, or 33% DW per node. Traps on processes 3 to 4 plastochrons younger than the first mature process (= P0) were empty, but the number of occupied traps increased rapidly, traps on process P1 were almost 100% tenanted. All traps with contents had some type of photosynthetic tenant, either cyanophytes, diatoms, green algae, or photosynthetic protists. Many traps also had living rotifers. The predominance of living organisms suggest that these traps support a community of microorganisms that function in nutrient cycling in these oligotrophic environments.


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