At the Morris Arboretum, Pennsylvania, US. May 14, 2024. @emery , this tiny little guy was not in a good shape. Most of the previous branches have died, and weak new growth from further back this year. The trunk is only as thick as my thumb. Also, it was very difficult to find, hidden in deep shade and out of sight for most visitors… I couldn’t find the second one on the ground. It may have died since 2021, when the inventory was created.
What an excellent and useful post, thank you so much. As I recall, (which means you can't totally count on my memory!) the maple was sown out with a project, sponsored by the Chinese Academy of Sciences, by the Kunming Botanical Garden. The result was a couple of thousand individuals, intended for ex-situ cultivation in order to retain the existence of the species, only growing on a few sites. Although the survey found more sites than originally expected. Though I'm sorry to see it's not doing better, it is a rare wonder.
@emery , I don’t know if you have seen the pictures on this site: https://uk.inaturalist.org/observations/135030553 It appears I may have missed the second specimen because I didn’t expect it to be so much larger than the first one. This one seems to be planted in a sunny spot. Pictures are from 2022, I can’t believe it has died since. For me, one of the most interesting features was the bark. You can see it even in the tiny specimen that I photographed peeling in very wide strips.
I will be in Boston in early August and will visit the Arnold Arboretum. They have 3 Acer yui, 2 from 2021 listed as “alive”, and one from 2008 listed in “fair “ condition. I will take some pictures.
It's interesting, some of the peeling bark on the Arnold pictures doesn't look like injury, but like the shaggy bark you see on (older) Acer buergerianum. It will be fascinating to see how closely yui is affiliated with that species, and if there is an affinity closer than the Series.
@emery , here is picture of the bark on a more established tree at the Morris Arboretum from the iNaturalist link I attached in post #3 in this thread.
