Most interesting, Jane. In our climate, that is a lot warmer than yours, N. thomsonianum is a super plant. Foliage is not floppy, and some flowers set a number of seeds, many small and aborted but also others that look large and complete. I assume the mother bulb dies here as well but the several large offsets are flowering size. Small offsets are also produced but not as abundant as in say, Fritillaria. The flower color is extraordinary, like a lavender with a small hint of blue, really lovely. From your description I assume N. thomsonianum could do very well in warmer climates. As for the other Notholirions they seem to prefer cooler conditions and were never happy here to eventually die off.