Development, Diversity and Dynamics of Plant Architecture in Utricularia subgenus Polypompholyx – Towards Understanding Evolutionary Processes in the Lentibulariaceae

Abstract

To uncover the nature of various kinds of stolons of Utricularia subgenus Polypompholyx (Lentibulariaceae) we studied branching of stolons by scanning electron microscopy, statistically investigated correlations of stolon types and other traits across 56 species, and evaluated seedling development and process morphological aspects. Some results were compared to the sister genera Pinguicula and Genlisea. A key to nine stolon types in Polypompholyx is provided. Predominant stolon types were rhizoids, runner stolons with rhizoids on nodes, and runner stolons without rhizoids on nodes but with bladders on internodes. Stolon types were taxonomically relevant and correlated to the distribution/climate. They obviously diverged with speciation events in Australia. Examined seedlings of Genlisea and Polypompholyx showed similar developmental patterns. Stolons were homologous to traps and leaves. Selected subterranean organs contained specific but similar process combinations of roots, shoots and/or leaves. We assume the Genlisea-Utricularia ancestor trap included processes of a Pinguicula root and leaf.

Cell Wall Microdomains in the External Glands of Utricularia dichotoma Traps

“…Recently, Carmesin et al [ 18 ] measured the hydraulic resistance of traps but did not observe water currents inside the traps of G. hispidula . Finally, species of the genus Utricularia (bladderworts) are also rootless as Genlisea , but with the more complex morphology of vegetive organs [ 19 , 20 ]. They form bladders ( Figure 1 ) with a high-speed suction mechanism [ 21 , 22 , 23 , 24 , 25 ].…”

The Localization of Cell Wall Components in the Quadrifids of Whole-Mount Immunolabeled Utricularia dichotoma Traps

“…All of the Utricularia species are rootless herbs. Their vegetative organs go beyond the typical organ classification, i.e., either ‘root’, ‘stem’, or ‘leaf’, and they have intermixed morphological traits and developmental programs [ 5 , 6 , 7 , 8 ]. These are related to the heterotopic transfer of the function of the genes to other organs, as was shown in the root genes [ 9 ].…”