The plant pictured below is called Sisal. As far as I know it is not native to Kenya, but was brought by the British 100 years ago as a plantation crop. Back then, this was the best substance for making rope, as the leaves are very fibrous, and strong. Though the Sisal market decayed rapidly with the invention of synthetic fibers such as nylon, Sisal is still and important crop in Kenya. However, it is more common to see these plants as items of landscaping rather than on a plantation.