s in summer) --3.

2a. Styles 5 =St. John's-wort, Hypericum kalmianum.=

2b. Styles 3 =St. John's-wort, Hypericum prolificum.=

3a. Flowers pinkish, 15 mm. broad (3-5 dm. high, in swamps)
=Marsh St. John's-wort, Hypericum virginicum.=

3b. Flowers yellow --4.

4a. Flowers about 4 cm. wide; principal leaves 5-10 cm. long (7-15
dm. tall) =St. John's-wort, Hypericum ascyron.=

4b. Flowers 8-25 mm. wide; stamens 15 or more --5.

4c. Flowers 1-10 mm. wide; stamens 12 or fewer (1-6 dm. high) --7.

5a. Petals dotted with black (4-8 dm. high) --6.

5b. Petals without black dots (2-5 dm. high)
=St. John's-wort, Hypericum ellipticum.=

6a. Flowers 20-25 mm. wide; leaves of an oblong type, broadest near
the middle =St. John's-wort, Hypericum perforatum.=

6b. Flowers 10-15 mm. wide; leaves of an ovate type, broadest below
the middle =St. John's-wort, Hypericum punctatum.=

7a. Leaves minute, subulate, 1-3 mm. long
=Pineweed, Hypericum gentianoides.=

7b. Leaves linear, with 1-3 principal veins, broadest near or above the
middle =St. John's-wort, Hypericum canadense.=

7c. Leaves lanceolate, 4-6 times as long as broad, with 5-7 principal
veins =St. John's-wort, Hypericum majus.=

7d. Leaves oblong, elliptic, or ovate, 1.5-3 times as long as broad --8.

8a. Uppermost bracts linear =St. John's-wort, Hypericum mutilum.=

8b. Uppermost bracts resembling the leaves in shape, but smaller
=St. John's-wort, Hypericum boreale.=

ELATINACEAE, the Waterwort Family

Small marsh herbs, with opposite leaves without translucent dots, and
inconspicuous axillary flowers. (Stems 2-5 cm. long; flowers in summer.)

One species in Michigan =Waterwort, Elatine americana.=

CISTACEAE, the Rock-rose Family

Small herbs or shrubs, with opposite or alternate entire leaves; flowers
regular, with 5 sepals, 3 or 5 petals, and 3 to many stamens.

1a. Flowers yellow (early summer) --2.

1b. Flowers greenish or purplish, minute, in panicles (late summer)
(Pinweed) --4.

2a. Leaves crowded, closely appressed to the branches; flowers
7 mm. wide (2-4 dm. high)