Off topic, sorry .
Summa summarum: Black mustard is Brassica nigra L./Sinapis nigra L.
Photo source
"Black cumin" stands for two different spices: Nigella sativa seeds; also known as "Black seeds" (the blue flowering plant in Morning Glory's post) or Bunium bulbocastanum/Bunium persicum seeds (pic below). Link to an article.
Summa summarum: Black mustard is Brassica nigra L./Sinapis nigra L.
Photo source
"Black cumin" stands for two different spices: Nigella sativa seeds; also known as "Black seeds" (the blue flowering plant in Morning Glory's post) or Bunium bulbocastanum/Bunium persicum seeds (pic below). Link to an article.