Figure 1. Stalked trapping glands (1) of a Drosera leaf. Once insects have touched the glistening droplets (2), each attempt to escape increases the number of attachments. Subsequently the stalked glands bend to the centre of the leaf where the prey is digested.

Figure 2. As typical pitchers, Nepenthes (drawn according to a photograph of Schmucker and Linnemann) attract insects by the often brilliantly coloured ribbed rims and the nectar glands between the ribs (1). Reaching the slippery internal waxy zone (2) just below, the prey drops into the digestion fluid (3) at the base of the pitcher lumen.

Figure 3. (a) A Dionaea flytrap (redrawn according to Juniper et al.) begins to operate when a trigger hair (1) on the leaf lamina (2) is mechanically stimulated. An electric potential is transmitted to the hinge of the mid-rib (3), inducing rapid closure. (b) In the closed state the trapped prey is prevented from escaping by the interlocked teeth (4). (c) The trap of Dionaea muscipula: note the three trigger hairs on the lobes of the leaf lamina and the long marginal teeth which are interlocked in the closed phase. Photograph by Maret Kalda, MPI, Cologne.

Figure 4. The Genlisea trapping device (redrawn according to Pietropaolo; slightly altered): The mouth (1) and its elongations into the two spiral arms (2) provide the entrances (3) for small aquatic animals as nematodes or copepods. The prey is directed by detaining hairs (4) and most probably also by negative hydrostatic pressure to the bulb (5), where they are finally digested.

Figure 5. (a) The internal four-armed glands (1) and the external globe-shaped glands (2) are involved in the generation of the strong negative hydrostatic pressure in the trap of the bladderwort Utricularia (redrawn according to Lloyd and Schmucker and Linnemann; altered). When the trap is set, the door exhibiting a hinge region (3) is attached to the velum (4) on the horseshoe-formed abutment (5). The trigger hairs (6) function as highly sensitive levers. (b) When the trigger hairs (Figure 5a, b) are touched, they bend the distal part of the entrance and the door is rapidly opened (6). To ease the tensions between the negative hydrostatic pressure of the lumen and the adjoining water, both the latter and the prey are speedily sucked in.