I owned some 80s "Black Million Flower" porcelain in their original unopened packing and had posted pictures of these pieces last year (link).
This label of 'Black Million Flower' is a name given by local porcelain collectors to this design that was produced in China in the 80s. If you read the Chinese writing on the box in the 2nd pix, the written description was 'ten thousand flower' design. I suppose and agree that 'million flower' sounded better for this porcelain.
I managed to get an unopened and mint in box 'million flower' tea set last month. As you will observe, this set came with a teapot, 4 cups and a tea tray. The tea tray, to me, was the highlight of the purchase. The colourful flowers that were hand decorated on the tray was very captivating. I believe that this is the only porcelain decoration made in China in the 80s that reflected the the bold colours and variety of flowers on a unique black background.
The only chop or seal markings on this set were only found on the bottom of the teapot (pix 3).