74 - 



la. 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, Hyperieum canadense. 



7c. Leaves lanceolate, 4 6 times as long as broad, with 5 7 prin- 

 cipal veins St. John's-wort, Hyperieum majus. 



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



8a. Uppermost bracts linear St. John's-wort, Hyperieum mutiliiin. 



8b. Uppermost bracts resembling the leaves in shape, but 



smaller St. John's-wort, Hypericiim 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. 



CIST ACE AE, 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. 



la. Flowers yellow (early summer) 2. 



Ib. Flowers greenish or purplish, minute, in panicles (late summer) 

 (Pinweed) 4. 



2a. Leaves crowded, closely appressed to the branches; flowers 

 7 mm. wide (24 dm. high) False Heather, Hudsonla tomentosa. 



2b. Leaves spreading; flowers 15 30 mm. wide (3 6 dm. high) 

 (Frostweed) 3. 



3a. Petal-bearing flowers solitary 



Frostweed, Helianthemnm canadense. 



3b. Petal-bearing flowers few, racemose 



Frostweed, Helianthemnm majns. 



4a. Stem-leaves linear, 4 or more times as long as wide 5. 

 4b. Stem-leaves oblong or elliptical, about 3 times as long as 

 wide (26 dm. tall) 8. 



5a. Plant pale with dense appressed pubescence (2 4 dm. high) 



Pinweed, Lechea stricta* 

 5b. Plant green, pubescence sparse or none 6. 



6a. Leaves thread-like, seldom exceeding 1 mm. in width (1 3 

 dm. tall) Pinweed, Lechea tennifolia. 



6b. Leaves 15 mm. wide (26 dm. high) 7. 



