Yucca

Throughout the desert and areas with low percipitation in the Known World, the plant yucca thrives. This is particullarly true in the Centralis Desert where it is one of the few edible foods which can be found growing in much of the desert.
Yucca is large bushy plant, standing upwards of eight feet (2.5 meters) tall, but more commonly around three feet (1 meter). The leaves when soaked and split into threads may be spun using normal cordage making techniques into excellent and strong cordage of varying diameters. The cordage is strong and durable, plus it's able to handle harsh conditions. The fruits, seeds, flowers, and stems are all edible, but care must be taken when harvesting.
Yucca roots can be dug, soaked, and roasted to make a delicious replacement for potatoes, sliced into fries, or cut into rounds.
The flowers of the yucca can also be used as a replacement for soap, and will lather nicely.
The leaves of the yucca plant are very sharp and great care must be taken when harvesting the plants or multiple cuts will cover ones skin. This is a most unpleasant experience, so be careful.
Rumour has it that the plant can also be used for bowdrill fires and the early seed pods may be edible.
Travellers in the desert often use the plant as the source of both food and cordage, the leaves can also be woven and used for blankets or tarps.
Settlements at the edge of the desert often cultivate the plant for all of the features mentioned above. A plant can easily feed a family of four for a whole meal.
Many different varieties of yucca exist across the Known World, and are often used by anyone who knows about them. Several of the native sentients use the plants also in the ways mentioned above.