The yucca plant common to the Southwest USA is also known as Spanish Dagger because of its sharp narrow leaves, pointed at the tips.
Spanish Dagger, a mystery novel by Susan Wittig Albert, sets its murder victim right in the middle of a patch of yucca. The body of a man is found by herbalist China Bayles while she was out gathering leaves of the yucca plant for a papermaking class.
Tidbits of herbal lore pepper the leaves of the novel, at the beginning of each chapter:
Tequila is made from the blue yukka (agave), sorry, I mean yucca, and has the same healing properties as the fresh plant. So no problem with those margaritas!
Juice from the Yucca plant is also good for lathering your hair and bathing.
Anyway, if you like your mysteries spiced with herbal lore, here is a book for you.