Jute comes from the jute plant and mainly grown in India and Bangladesh. The fibre produced to form a course string or rope like yarn that is pliable making it easy to weave. Jute can be dyed to give the rug colour but it does not perform well in wet areas because it has a tendency to absorb. The down side is this also means it is prone to staining.
Seagrass is a grass grown in saltwater marshes around the coasts of India and China. Because the whole reed is used in the fibres production it means it is extremely, durable, stain and water resistant. The fibre cannot be dyed therefore is only available in its natural colouring which often starts with a greeny hue that fades lighter over time.
Sisal is a derivative of the cactus and is grown in South America and Africa. The fibre is stipped from the fleshy leaves of the cactus plant then dried and spun into a creamy coloured yarn. Sisal has a harsher feel than jute and therefore is more durable. Also, like jute it is very absorbent meaning it can be dyed so you can have colour in your natural rug. While like jute sisal will also stain easily, on plus side it will absorb moisture from the air in humid areas. Of course there are many rugs that also offer a mix of these fibres which can work well when producing a rug that is both durable and aesthetically pleasing.