Yucca brevifolia

Rumor is that Joshua held out his pointy spear on a hill, watching Israelis sack the city of Ai.  That old town had the misfortune of being in the Promised Land.  He drew it not back until the Jews won.

And the king of Ai he hanged on a tree until eventide: and as soon as the sun was down, Joshua commanded that they should take his carcass down from the tree, and cast it at the entering of the gate of the city, and raise thereon a great heap of stones, that remaineth unto this day.   - Joshua 8

The pile of rocks is out there in the Mojave, next to the trees with javelin leaves.  It's a bunch of quartz monzonite and tall monoecious plants.  No trees, only sharp, biblically intense yucca.  John C. Frémont saw that story in a blazing desert under ranks of flailing spearish gallows.  The Colonel spent a lot of time around bayonets.  One of his hobbies was botany.  The other was War.  He wandered the West for years.  I'm guessing he only brought one book.

We went there to climb irreverently upon the stones.  They lie indeed in huge heaps, fitting backdrop for giant sloths lost to fossil rumor.  Secret boulder crypts, a distant desert forest.  We busied ourselves at moonset bouncing light onto plants.  If you bring just one book today, make it McPhee's Annals of the Former World.  The past is present, the present is past, and so on.  Tall yucca still arbor the sun and twisting stars.  Cue the U2 and tend your torn fingers.  They're Joshua Trees.