1	"Functional stamens 2, staminodes 1"	Cypripedium
1	"Functional stamens 1, staminodes 0"	2
2	"Leaves 0 at flower"	3
2	"Leaves present at flower"	6
3	"Flower spurred, without mentum"	Piperia
3	"Flower not spurred, with mentum or not"	4
4	"Flowers in spiral, lip pouch-like"	Spiranthes
4	"Flowers not in spiral, lip not pouch-like"	5
5	"Plant white, becoming +- yellow or brown"	"Cephalanthera {Cephalanthera austiniae}"
5	"Plant brown, tan, +- pink, +- red, +- purple (+- green)"	Corallorhiza
6	"Leaves cauline"	7
6	"Leaves +- basal"	9
7	"Leaves 2, +- opposite, +- at mid stem"	Listera
7	"Leaves > 2, alternate, along stem"	8
8	"Leaves with > 1 lengthwise fold, green, white, or pink; flower not spurred"	Epipactis
8	"Leaves with 1 lengthwise fold, green; flower spurred"	Platanthera
9	"Leaves 1(2)"	10
9	"Leaves > 1"	11
10	"Flowers 1, lip pouch-like"	"Calypso {Calypso bulbosa var. occidentalis}"
10	"Flowers > 1, lip not pouch-like"	"Malaxis {Malaxis monophyllos var. brachypoda}"
11	"Leaves in rosette"	"Goodyera {Goodyera oblongifolia}"
11	"Leaves not in rosette"	12
12	"Flowers not in spiral, spurred"	Piperia
12	"Flowers in spiral, not spurred"	Spiranthes