The Differences between Indica and Sativa Cannabis plants:
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.
Here is a quote from Hilary Black of the British Columbia Compassion Society:
“Indica and Sativa are the two main varieties of the cannabis plant used as medicine. There are many strains that are crosses of those two varieties. Within each of those varieties and crosses there are a huge number of individual strains, each with a different cannabinoid profile and effect. According to anecdotal evidence, the Indica strains are a relaxant, effective for anxiety, pain, nausea, appetite stimulation, sleep, muscle spasms and tremors, among other symptoms. The Sativa strains are more of a stimulant, effective in appetite stimulation, relieving depression, migraines, pain and nausea. We are now aware of specific strains that are effective for specific conditions and symptoms.”
Source and more info: http://www.weedfarmer.com/growing_guide/cannabis_indica_sativa.php