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.
Family, Nettle. Flowers of two kinds, stami-nate and pistillate. Corolla wanting. Sepals 3, a hooded scale in front of each. In the pistillate flowers, one large sepal incloses the seed, an achene, in fruit. From the resemblance of this sepal to a cap, the name is derived (pileus, a cap). Leaves, pointed, 3-ribbed, coarsely toothed. Stem smooth, 3 to 18 inches high. July to September.
Cool, moist, shady places.
 
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