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.
This has a white root, whence its common name. It grows 1 to 3 feet high, with narrow, smooth leaves, the stem thickly branched, coarse in its growth, like most of this genus.
© 2007-2017 StasoSphere.com