There has been some confusion all over about differences of Indica and Sativa plants. Here are a few rule of thumbs: Fat Leaves and Short Bush = INDICA Thin Leaves and Tall Bush = SATIVA Indica....higher CBD than THC equals heavier, sleepy type of high. Yield is usually higher than Sativa, and shorter growing season. Better for indoor growing, because they don't get as tall. Sativa....higher THC than CBD equals cerebral, soaring type of high, more energetic Yield is usually lower than Indica, but is very potent. eg: Thai Sativa grow taller and have a longer flowering period, so they are better suited for outdoors. Sativa's typically take longer to germinate and flower, and they grow more gangly then indica breeds. Link to article:http://www.a1b2c3.com/drugs/mjgrow9d.htm Edit: Another link with great information: http://www.medicalmarihuana.ca/strains.html