How to Grow Broccoli Raab (Brassica rapa Ruvo) - Gardening Channel
Kale, Brussels sprouts, cauliflower, and cabbage are all varieties of a single magical plant species - Vox
Brassica Oleracea Plant Species Vegetables: Kale, Broccoli, and More
Artificial selection - Understanding Evolution
Did you know broccoli is a human invention? It doesn't grow in the wild and was selectively breeded from the wild mustard plant. Same goes for these: - 9GAG
Broccoli Companion Plants: the Good, Bad, and Best
One Mustard, Many Flavors — In Defense of Plants
How Does Broccoli Grow
Brassica oleracea - Wikipedia
Do broccoli and cauliflower come from the same plant? - Quora