ra biennis.=

7b. Stem and foliage densely but closely appressed-pubescent
=Evening Primrose, Oenothera rhombipetala.=

8a. Petals 5-10 mm. long =Sundrops, Oenothera pumila.=

8b. Petals 14 mm. long or more =Sundrops, Oenothera fruticosa.=

9a. Petals 2, reverse heart-shape, stamens 2 (flowers small, white,
summer) (Enchanter's Nightshade) --10.

9b. Petals 4; stamens 4 or 8 --12.

10a. Leaves rounded at the base, denticulate (3-8 dm. high; fruit
prickly) =Enchanter's Nightshade, Circaea lutetiana.=

10b. Leaves cordate at the base --11.

11a. Fruit 2-celled, bristly (2-4 dm. high)
=Enchanter's Nightshade, Circaea intermedia.=

11b. Fruit 1-celled, with soft hairs (delicate plant 2 dm. high, or
less) =Enchanter's Nightshade, Circaea alpina.=

12a. Petals entire (summer) --13.

12b. Petals notched at the end (flowers white or pinkish, less than
1 cm. broad, in summer) (Willow Herb) --15.

13a. Flowers 2-3 cm. wide, purple (7-20 dm. high)
=Fireweed, Epilobium angustifolium.=

13b. Flowers about 1 cm. wide --14.

14a. Flowers red (2-5 dm. high) =Gaura, Gaura coccinea.=

14b. Flowers white, turning pink when old =Gaura, Gaura biennis.=

15a. Leaves entire, the margins usually somewhat revolute --16.

15b. Leaves toothed, flat (4-9 dm. high) --18.

16a. Plant densely pubescent with spreading hairs (3-8 dm. high)
=Willow Herb, Epilobium molle.=

16b. Plant pubescent with appressed or incurved hairs --17.

17a. Leaves linear, the margin revolute (3-5 dm. high)
=Willow Herb, Epilobium densum.=

17b. Leaves narrowly lanceolate, not revolute (2-4 dm. high)
=Willow Herb, Epilobium palustre.=

18a. Seeds tipped with a tuft of reddish-brown hairs
=Willow Herb, Epilobium coloratum.=

18b. Seeds tipped with a tuft of white hairs
=Willow Herb, Epilobium adenocaulon.=

HALORAGIDACEAE, the Water Milfoil Family

Aquatic or marsh herbs, with alternate, opposite, or whorled leaves, and
small, inconspicuous terminal or axillary flowers, frequently without
petals (summer).

1a. Leave