Oh yeah. Brassica rapa has your turnip, napa cabbage, bok choy and rapini/rabes. Brassica napus gives canola oil, swedish turnip, and rutabaga. Mustard comes from B. juncea, B. nigra and B. hirta.
Also those species names aren't really even guaranteed to be accurate because biologists, botanists, geneticists, etc, can't even really agree on where to draw the line.
There's a whole genre of Brassica memes and it's fantastic.
