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, Mint. Color, light purple. Calyx, 5-toothed, bell-shape, rather hairy. Corolla, with a narrow, long tube and spreading border. Flowers, in clusters of 4 to 6 growing in the upper leaf-axils. Stem, slender, erect, 8 to 18 inches high, hairy along the joints. Leaves, long and narrow, thin, pointed at both ends, with short petioles or sessile. July to September.
In moist fields or wet, sandy soil, Massachusetts to Florida, west to Michigan.
 
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