I'm growing two Mustard Bhutlah plants. One of them has black on its leaves and fruits. It started out having a lot of black, but soon a lot of the black dissipated. The stems and branches are black, except on the lower half of the plant. One of the fruits appears to be all black. I discovered that it had set five fruits by 13 Aug 2019. It seems to have fewer flowers per node than the other Mustard Bhutlah, but it does have multiple flowers on some nodes.
The anthocyanin plant is producing before the other plant. I'm pretty excited that it has fruits. I should be able to grow it again next year (without taking cuttings). My Mustard Bhutlah's are the only C. chinense peppers to have flowered. I have some Habaneros growing, but they've been stunted.
Anyway, of this species, I only plan to grow Mustard Bhutlahs next year.