I think that this is the fifth winter where self sown seedlings of a mystery brassica veggie have appeared in a baby pool garden. Each year they come up, bear wonderful leaves, bloom in spring then drop seeds, each time always different from preceding years. The first two years they were clearly seedlings of/pollinated by 'Purple Kosatai' with lavender tones in the stems....but this year they so far are green, looking pretty much like young plants of any one of a number of Chinese Cabbages.