For the record, Euphorbias are not Cacti. That said, I found an awesome Euphorbia lactae at Koolau Farmers.
So as much as it looks like it - the E. lactea is not a cacti (convergent evolution).
Our stop at Once Again Succulents was fun also. The kids picked up their own Portulaca molokinensis and I found a Monadenium ritchiei
We're so glad to be able to 'plant roots' and work with plants - moving so frequently has given us experiences we will never forget, but for now we finally get to enjoy exercising our green thumbs.