On 7 Nov 2014, at 20:30, T O wrote: > This brings to my mind a perplexing question. Dutch growers often retire > certain cultivars that cease to grow well once the clones acquire too many > viruses (King Alfred). Is it really possible that a single saffron clone > could go on for thousands of years without acquiring too many viruses, or > even just succumbing to old age? The "Giant Yellow" crocus, a hybrid between two yellow species that I forget the identities of, is still one of the strongest growing crocuses, though it's hundreds of years old. Going a little further afield, dahlia 'Bishop of Llandaff" is over a century old and still thriving. At least some monocots appear to be immune or resistant to virus-induced loss of vigor, so why not the saffron crocus? I have no idea what mechanism lies behind this apparent immortality. -- Rodger Whitlock Victoria, British Columbia, Canada Z. 7-8, cool Mediterranean climate