Hey Josh,
Glad to hear that you were able to successfully graft chemp onto jack, as jack rootstock so plentiful now that even Publix is stocking them. Wanted to share some pics of the seedlings I’m growing, purchased these seeds from maryoto (if I remember correctly) from Borneo and the chempedak is definitely the hairy one, meanwhile this other one is like jack x chemp cross and has leaf characteristics like chemp but the non hairyness of jack.
Here is a reference you might be interested is as well, seems there is some variation amongst samples the authors identified based on interbreeding with wild chempedak (bangkong). https://arch.library.northwestern.edu/downloads/4j03cz67q?locale=en
-Joe
That looks pretty good! Maybe you can add a jack rootstock to the one on the right and get it to perk up. I have killed so so many chempedak seedlings. Are you going to plant them out in yard?
I found this as well looking for the wild silvestris info.
https://bsapubs.onlinelibrary.wiley.com/doi/full/10.1002/ajb2.1094"However, bangkong is very difficult to differentiate from cempedak when not in fruit. Morphological differences between cempedak and bangkong reportedly include variation in pubescence, color of withering leaves, size of male inflorescences, size of fruits, and most notably the lack of fragrance and insipid taste of the bangkong fruit (Corner, 1938; Kochummen, 1978). In contrast with the cultivated cempedak, bangkong fruit is harvested only for its seeds, typically by the Orang Asli, the indigenous peoples of Peninsular Malaysia. Bangkong seeds take longer to cook, but their fluffy texture is favored more than the sticky texture of cempedak seeds"
I wonder if the Durian Chempedak is a cross with var Silvestris. It looks different and has a more mild creamy taste. They also seemed to be easier to grow even though I killed them.