If you need to make a quick sewing repair to clothing or camp equipment, the yucca plant provides a needle with thread already attached. Pictured below: Yucca plant
Locate a yucca plant and cut a long leaf from the plant.
The sharp spine on the end of the leaf will be your needle. Use you knife and start a small cut down each side of the needle leaving a strip of yucca leaf that is about a quarter inch wide. Pictured below: splitting fibers from the sides of the needle with a knife.
Use your fingers to strip off the fibers on the outside edges of the leaf. Pictured below: Stripping of the outside fibers.
Use your knife and starting about an inch-and-a-half below the needle scrape off the waxy outer layer of the leaf. Pictured below: Scraping of the waxy outer layer.
Starting about an inch and a half below the point of the needle, split the exposed yucca fibers into two strand and twist these strands together to form your thread. Pictured below: top, Splitting the fibers with a knife; middle, separating the fibers into two strands with the fingers; bottom, Twisting the strands into thread.
You should now have about a foot to foot and a half long thread with a needle attached to it. The needle will easily penetrate cloth. If you are going to sew leather or canvas you will probably have to use an awl to punch holes in the material first. Pictured below: top, Finished needle and thread; bottom, sewing cloth with the yucca needle and thread.