My #3 plant has no odor, what gives?

I currently have 3 plants in a CFL setup and i have noticed that my number three plant has no noticable odor to it. However, my other two plants have that distinct natural aroma to them. Why is this? Could this be a precurser towards a male? Im not sure whether the males have an aroma to them? I have never seen a live male plant before. Any ideas?
 
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