Cucumber Skin Barbs
Under 800X magnification, this honorable-mention-winning photograph shows toxin-filled barbs called trichomes on the skin of an immature cucumber.
The trichomes bear sharp points 40 times thinner than a sewing needle and help protect the growing fruit from predators. The toxins they release are called cucurbiticins and are the most bitter compounds known.
Image: Dr. Robert Rock Bellivea