The California Manroot, Marah fabaceus, is a fascinating plant we find here in the Sierra foothills. A native vine, it produces a distinctive seed pod, covered in spines. Below are photos of the fruit, showing the seeds it produces. It appears to me that the fruit bursts open due to gas pressure inside. I failed to witness the actual opening, but shortly afterwards, I heard the seed pod release gas. This pod produced 17 seeds.
Click on an image to enlarge it.