Crocus and Saffron crocus

Crocus noun - Any of numerous low-growing plants of the genus Crocus having slender grasslike leaves and white or yellow or purple flowers; native chiefly to the Mediterranean region but widely cultivated.

Saffron crocus and crocus are semantically related. In some cases you can replace phrase "Saffron crocus" with "Crocus", this terms are similar.

Saffron crocus noun - Old World crocus having purple or white flowers with aromatic pungent orange stigmas used in flavoring food.

Crocus and saffron crocus are semantically related. You can use "Crocus" instead a noun phrase "Saffron crocus".