Figure 2
From: Trap diversity and character evolution in carnivorous bladderworts (Utricularia, Lentibulariaceae)
SEM images showing morphological trap characteristics of U. gibba (representing the UVTT 1) and of U. resupinata (representing the UVTT 2). (A) Sagittal section of a trap of U. gibba. The entrance forms a short tube. The trapdoor, the threshold, and the different glands covering the trap inside are clearly visible. (B) Sagittal section of an U. resupinata trap entrance. Note the cavity on the threshold, the free door edge, the trigger hairs, the velum and the threshold. (C) Exterior view on trap entrance of U. resupinata. The trigger hairs, the free door edge and a multitude of glandular structures are visible. (D) Sagittal section through the short trap entrance of U. gibba with the trigger hairs, the door edge and distinct velum and cavity on the threshold clearly visible. (E) Exterior view on trap entrance of U. gibba. (F) Concentric cellular constrictions on the inner door surface of U. gibba, with different door regions sensu [15] indicated. Scale bars 100 µm. Abbreviations: c = cavity, ch = central hinge, de = door edge, mp = middle piece, mr = middle region, th = threshold, tr = trigger hairs, v = velum.
