Joan got it right….
I believe it is part of the yucca plant. I remember my grandmother bringing
one from Mexico many years ago to show me "how the needle was already
threaded."
The 170-plus species of agave in Mexico are the country’s original multi-purpose plants and for centuries people throughout the country have found many good uses for them – ranging from the improvisation of an instantaneous needle and thread (simply pull one of the spiky leaf-ends along the edge of the leaf), to fiber for making sandals, weaving clothes or compressing into paper, to various drinks, some involving fermentation and distillation, to soap and even as an instrument of punishment or torture.
We watched as the lady demonstrating snapped off the end of the leaf, stripped the leaf and extracted a piece of tissue like tracing paper which was used a paper and then the tip of the cactus had long strands of thread attatched. So you have a ready threaded
needle…..
Amazing.