This section is from the book "Harper's Guide To Wild Flowers", by Caroline A. Creevey. Also available from Amazon: Harper's Guide To Wild Flowers.
B. Beckii - Color, yellow. This is an aquatic, with simple or somewhat branched stems, 2 to 8 feet long. Leaves, those under water many, cut into fine, hair-like segments; those above, out of water, a few, sessile, long, narrow, undivided, serrate. August and September.
A large-flowered species, found in slow streams and ponds. The flowers are single, on long or short peduncles. The seeds are smooth nutlets, each with several long awns, spreading apart, barbed at their apex.
 
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