Influence of Sarracenia purpurea (Purple Pitcher Plant) morphology on prey biomass and inquiline number.

Abstract

Nitrogen is a critical limiting nutrient for terrestrial plants, especially in the nutrient-deficient soil of Sphagnum bogs. The purple pitcher plant, Sarracenia purpurea, survives in nutrient-deficient bogs by capturing nitrogen from prey organisms. Inquiline organisms live inside pitchers and influence the amount of nitrogen available to the plant. Because pitcher plants obtain nitrogen from prey, it is essential that they attract prey organisms to their pitchers. We determined whether pitcher hood color and venation play a role in attracting prey organisms. We analyzed 47 pitchers from different plants for the mean green-red ratio of their hoods, total vein length, prey biomass, number of inquiline organisms, and insect-derived nitrogen. Pitchers with higher green-red ratios attracted more prey, and plants that captured more prey had more insect-derived nitrogen. Pitcher hoods with more venation attracted less prey. Inquiline organisms did not appear to influence the amount of insect-derived nitrogen in the pitcher plant. In spring, pitchers with a higher green-red ratio and less venation apparently have an advantage in attracting prey.