RT Journal Article
SR Electronic
T1 The Fern Sporangium: A Unique Catapult
JF Science
JO Science
FD American Association for the Advancement of Science
SP 1322
OP 1322
DO 10.1126/science.1215985
VO 335
IS 6074
A1 Noblin, X.
A1 Rojas, N. O.
A1 Westbrook, J.
A1 Llorens, C.
A1 Argentina, M.
A1 Dumais, J.
YR 2012
UL http://science.sciencemag.org/content/335/6074/1322.abstract
AB Various plants and fungi have evolved ingenious devices to disperse their spores. One such mechanism is the cavitation-triggered catapult of fern sporangia. The spherical sporangia enclosing the spores are equipped with a row of 12 to 13 specialized cells, the annulus. When dehydrating, these cells induce a dramatic change of curvature in the sporangium, which is released abruptly after the cavitation of the annulus cells. The entire ejection process is reminiscent of human-made catapults with one notable exception: The sporangia lack the crossbar that arrests the catapult arm in its returning motion. We show that much of the sophistication and efficiency of the ejection mechanism lies in the two very different time scales associated with the annulus closure.