Thanks for that, Steve; it is interesting
and useful.
The Chinese form has a short dormancy, too, but I'm not sure it correlates with the Taiwanese form. I am sure it is more cold hardy than the Taiwanese form, but certainly not hardy enough for Minnesota, so I overwinter them in the fridge. They always sprout while in the fridge around January, along with L. pomponium and rhodopeum. (I am not saying I grow any of these well, but there you are...)
Again, I'm not saying I grow them well, but from seed they have tended to be rather short lived above the ground, spending a lot of time doing "nothing". This is the first year I have had a couple stay green through the whole summer, and only now are they turning yellow. So I think the Chinese form isn't necessarily dormant in the summer months. Even though Minnesota summers are normally not as hot as the rest of the country, this year was exceptional with almost a month straight of 90°plus days that started on June 20th! And it stayed abnormally hot throughout, even into October. Yet, this is the year my Chinese seedlings stayed green the longest.
There is so little congruency with environmental factors, that it is incredibly difficult to even formulate hypotheses.
I am not familiar with what happens with plant growth in general during natural monsoon seasons. One might think this would be the time to grow with lots of natural rain that would bring small amounts of nitrogen with it. In addition, it is the wetter soils (but still airy) that soil flora, including mychorrizae, love compared to just moist soil. This in turn would convert more organic matter into useful nutrients forms for plant uptake. Yes, the monsoons would bring more dreary days, but the summer season has longer days, too.
I recall an account by a contemporary plant "explorer" looking for L. polyphyllum when it would normally bloom and the rains started early that year, so he had very tough going there in Kashmir, I think it was. What makes sense to me is that any lily would evolve to bloom before a monsoon season begins, because rain and humidity make good pollination unlikely.