image: These are three capsules from Sphagnum henryeuse. Two are round (unexploded) and one that has already exploded. Each capsule, on elongated pseudopodia (stalk), has a clearly defined circular opening topped by a cap. The shape change from round (unexploded) to cylindrical or vase-shaped (exploded) shows how the contents of the capsule are compressed contributing to the 2-5 atmospheres of pressure that build up internally that drive the explosion and formation of the vortex ring. This image relates to an article that appeared in the July 23, 2010, issue of Science, published by AAAS. The study, by Dr. D.L. Whitaker at Pomona College in Claremont, Calif., and colleagues is titled, "Sphagnum Moss Disperses Spores with Vortex Rings." view more
Credit: Image courtesy of Joan Edwards