Indian mustard, Brassica juncea

Brassica juncea or Brassica nigra? They look a lot alike. Ever get a mental block and lose track of something? "Turn right up there - no, I meant left!" For me, this one has persisted. Is it the one with fruit close to the stem? Is it the one with flowers above the buds? Is it the one with longer fruit? It's all that, but it isn't always that straight forward. The flowers and buds themselves sometimes seem to get confused about which they are. And the fruit doesn't hug the stem until it matures a little. An image of just the flowering part won't show that key, or the size of the fruit. At least I'm not alone. There's a mention of this confusion in Michigan Flora as a possible reason this widespread species isn't represented by more specimens in their herbarium. It is widespread, growing in every state and province except LB, and maybe NU. There's more confusion, since Nunavut wasn't separated from the Northern Territories until 1999, after most botanical texts about Canada's plants were published. Beal Gardens, MSU, 5/24/12 (certainly we can depend on MSU to get it right! Uh, well, no, everybody makes mistakes.) Mustard family, Brassicaceae.