question about botanical names
i have been working at a health food store for a year now. in this time i have noticed four seemingly different plants (since visiting this site i see many more). if i miss spell any of these please excuse me, spelling was never my strong suit, avena sativa(oats), lettuca sativa(lettuce),canabis sativa(marijuna), and sativa(alfalfa).
my question is, what does sativa represent, what does it mean? i don't see a visible connection to these plants, or to a pear or any of the others mentioned in my search of sativa.if any one could please tell me! i have been looking through all the books i can get my hands on and it is driving my crazy! it seems that every day i find more with that name.