1	"Leaf margins entire or with few inconspicuous teeth"	2
1	"Leaf margin with small teeth"	3
2	"Leaves to 2.5 cm wide, margins with curly white threads"	"Yucca filamentosa"
2	"Leaves to 5 cm wide, the margins without threads"	"Yucca gloriosa"
3	"Plants freely suckering, leaves 4–6 cm wide"	4
3	"Plants generally solitary, leaves 0.8–1.5 cm wide"	5
4	"Ovary stalked; flowers often tinged purple"	"Yucca aloifolia"
4	"Ovary stalkless; flowers not purple-tinged"	"Yucca elephantipes"
5	"Leaves 0.8–1 cm wide, margin white"	"Yucca schidigera"
5	"Leaves 1–1.5 cm wide, margin yellow"	"Yucca whipplei"