This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
Beautiful herbaceous perennials closely related to the Buttercups, and valuable for moist borders, rock gardens, etc, but will also flourish in good rich garden soil. They are increased by division, and a fair trade is done in the roots in spring or autumn. The following are the best kinds: asiaticus, 1-1½ ft., with its deeper-coloured variety "Orange Globe"; and japonicus, Fortunei, and major - all with fine yellow blossoms. T. europoeus is a native species, 1-2 ft., having clear-yellow flowers in summer.