“ It is propagated mainly from the roots, one ton being required to plant an acre. The land is prepared and cultivated as for other root crops. Harvesting may begin after the plant has made its full period of growth, but it has been found that the percentage of tannin increases as the roots lie dormant in the ground. In the wild state the plant makes its growth during the winter and early spring, and by early June has seeded and the tops are dead. About fifteen tons of roots per acre is an average yield. The preparation for the market consists in slicing the roots and drying them in the sun. ”