Here's a video of me using Sotol on Sotol for the hand drill.
I wasn't sure which species this was when I harvested it. I knew that several Yucca species are useful for the hand drill, and this large stalk looked like one that was worth trying. I researched the different species of Yucca, and none of them was a very good match. Then I stumbled across a picture of Sotol. Bingo! Sotol looks just like one of the many Yucca species. Sotol and Yucca belong to the same classification family. But they diverge at the subfamily: Yucca belongs to the Agavoideae subfamily whereas Sotol belongs to the Nolinoideae subfamily along with other "evergreen shrubs". In my uneducated opinion, it looks a lot more like an Agavoideae than a Nolinoideae. In this video I refer to this plant as Yucca because at the time, I hadn't ID'd it yet. But now I'm pretty sure it is actually Sotol, Dasylirion wheeleri.
Sotol is the second plant I've used successfully for the hand drill. I've made embers using this sotol five times. In the process of trying to make this video, I made four embers. But each time I tried to use the ember to start a fire, I failed. If anyone has an idea why I couldn't get the ember to light a fire, please let me know.
About three weeks ago I collected this stalk and just now got around to trying it out. I'm very pleased with it as hand drill material. It's nice to be able to use the same plant for both the hearth board and the spindle. It's as easy to form an ember with sotol as it is with mullein, in my opinion. It may appear more difficult in this video, but keep in mind that this video shows the fourth successful ember in a row. And by the fourth time I was pretty exhausted.
The next material I'd like to try to use is Prickly Lettuce. It's very abundant here in Austin TX, so being able to use it would ensure an almost endless supply. I've been watching it mature and waiting to harvest it. Hopefully I'll be able to collect some stalks in the next few weeks.