rolla
regular, with 4-5 petals; stamens as many or twice as many; ovary
3-10-celled, with 1 style.

1a. Plants without green color; leafless or with scale leaves only --2.

1b. Plants with green leaves --4.

2a. Flowers solitary (1-2 dm. high; summer)
=Indian Pipe, Monotropa uniflora.=

2b. Flowers in clusters --3.

3a. Petals united into a bell-shape corolla (3-9 dm. high; summer)
=Pine Drops, Pterospora andromedea.=

3b. Petals all separate (1-3 dm. high; summer)
=Beech Drops, Monotropa hypopitys.=

4a. Leaves all basal; herbaceous plants with terminal racemes (1-4
dm. high; summer) (Shin-leaf) --5.

4b. Stem-leaves present --12.

5a. Style straight --6.

5b. Style bent near the apex --8.

6a. Racemes one-sided, the flowers all turned in one direction
(flowers white or greenish-white) --7.

6b. Raceme regular, the flowers not all pointing in the same
direction (flowers white or pink) =Shin-leaf, Pyrola minor.=

7a. Flowers numerous in each raceme =Shin-leaf, Pyrola secunda.=

7b. Flowers only 3-7 in each raceme
=Shin-leaf, Pyrola seconda var. obtusata.=

8a. Flowers pink or purple --9.

8b. Flowers white or greenish --10.

9a. Leaves cordate at base =Shin-leaf, Pyrola asarifolia.=

9b. Leaves rounded at base, not cordate
=Shin-leaf, Pyrola asarifolia var. incarnata.=

10a. Leaves shining on the upper side; sepals one-third as long as
the petals =Shin-leaf, Pyrola americana.=

10b. Leaves dull on the upper side; sepals one-fourth as long as
the petals, or a little shorter --11.

11a. Leaf-blades mostly shorter than their petioles, thick and firm
=Shin-leaf, Pyrola chlorantha.=

11b. Leaf-blades thin, usually longer than their petioles
=Shin-leaf, Pyrola elliptica.=

12a. Petals nearly or quite separate from each other --13.

12b. Petals united into a gamopetalous corolla, the tube of which
is as long as or longer than the lobes --18.

13a. Leaves opposite or whorled; stems herbaceous or nearly so (summer)
--14.

13b. Leaves alternate; stems shrubby (early summer) --16.