It's called Ruderalis. The only strain I know of thats cannabis Ruderalis is called 'Lowryder'. It's good because it's autoflowering (no need to change light cycles) and it only grows to a maximum of 2 feet, often shorter. However, because of the short size you can expect to only get a small yield (around 20 grams per plant, occasionally an ounce), although yields of 2 ounces per plant have been recorded if grown hydroponically. From germination to bud, expect to wait around 60-70 days at most. The potency is actually supposed to be quite good - for such a small and easy to grow plant anyway - at around 7-10%.
I have'nt grown this strain myself, but I am planning to grow this and Durban Poison outdoors later in the year.
Lowryder has been found to be an excellent plant for beginners, as it can grow it the harshest of climates and is extremely disease resistant. I think it's about 65% indica and 35% sativa, so a pretty good wake n' bake strain.