My yunnanensis suffered fertilizer toxicity in August when it was also greatly stressed by the heat. It stop putting out new leaves and just stopped growing. No growth occurred for a month and a half until we got our first cold spell which dropped night-time temperatures into the 60s(F) and mid 80s(F) for daytime highs. The yunnanensis and itinerans responded well and began growing again. The new leaves are normal and not "fertilizer burned."
My larger yunnanensis does not have the dark purple color on the dorsal midrib if I remember correctly, I will check and photo document that tomorrow.
I don't remember covering "corrugated lamina" in my Botany class, or any lamina for that matter, what is that?
Also on mine the purple-black splotching is not sparse, and is very abundant, while the petiole wings are strongly clasping.
Is the Novon description for M. y. yunnanensis or a general M. yunnanensis descriptor?
Thanks to both of you for your observations and direction!
