This is Citronella (Cymbopogon nardus). It is dark green, broad in size, has reddish stems and a strong smell when crushed. Citronella is not for consumption. It is effective as a "mosquito repellent, floor cleaner and in household disinfectants".
This is lemon grass (Cymbopogon citratus), also called fever grass in Guyana. It is a lighter green than the Citronella, thinner and actually smells like a citrus. Lemon grass is used as "food fragrance, remedy for cough and cold, antioxidant, pain reliever and antibacterial."
We use it in our tea and juice blends. Try it with Sorrel, Basil or Sweet Sage.