Thanks Lin, comparing the two side by side they do look to be the same. The younger plants are not that much different in leaf shape, they might change a little as the plants mature. The stems look the same too.
It must take a lot of heat to open the seed pods, I had a couple, one in the ground C. rigidus for years but the very hard winter 2010/11 killed it. It had tons of seed pods on but they never opened!
