Original caption: "(A) <i>N. gracilis</i> pitcher with visiting <i>Polyrhachis pruinosa</i> ant, showing the epicuticular wax crystal surfaces on the inner pitcher wall and on the underside of the pitcher lid. (B) The horizontal orientation directly above the pitcher opening puts the lower lid surface in an ideal position for prey capture."
Bauer <i>et al.</i>
CC BY 2.5
Bauer, U., B. Di Giusto, J. Skepper, T.U. Grafe &amp; W. Federle 2012. With a flick of the lid: a novel trapping mechanism in <i>Nepenthes gracilis</i> pitcher plants. <i>PLoS ONE</i> <b>7</b>(6): e38951. <a href="https://en.wikipedia.org/wiki/Digital_object_identifier" class="extiw" title="w:Digital object identifier">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1371%2Fjournal.pone.0038951">10.1371/journal.pone.0038951</a>