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.
These were more extensively grown some years ago than at present, but there is still a large demand for them for the decoration of conservatories, etc. The numerous hybrid varieties are far superior to the native South American species from which they have sprung. The catkin-like tubers are potted up in rich sandy soil, or leaf cuttings may be rooted readily to increase the stock. A stove temperature and treatment is best, the plants being in season from spring till autumn, and then taking a rest.