In: Phyton, 49 Fasc. 2 (2010), S. 241-251

Key words: Aquatic carnivorous plants, Lentibulariaceae, dystrophic water, growth rate, investment in carnivory, photosynthetic and carnivorous shoots.

Summary

Adamec L. 2010. Field growth analysis of Utricularia stygia and U. intermedia – two aquatic carnivorous plants with dimorphic shoots. – Phyton (Horn, Austria) 49 (2): 241–251.

A detailed 14-d growth experiment on two temperate aquatic Utricularia species with dimorphic shoots, U. stygia and U. intermedia, was conducted at two natural shallow dystrophic sites in S Bohemia, Czech Republic. Both sites were oligo- to slightly mesotrophic, and dissolved O2 and free CO2 concentrations were sufficient so as not to limit plant growth. Both species exhibited a similarly high apical growth rate of photosynthetic shoots (1.9–2.1 leaf node d–1), as is reported in the literature for aquatic Utricularia species with monomorpic shoots. Moreover, the estimated doubling time for biomass of the two species (6.6–9.2 d) represents the absolute maximum growth rate ever estimated for an aquatic carnivorous plant (Aldrovanda, Utricularia spp.). These findings thus clearly support the ecophysiological concept that aquatic carnivorous plants differ greatly from their terrestrial counterparts in their very rapid growth.