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.
A small trade is done in these shrubby plants with evergreen leathery leaves and flattish blue or purple flowers. The best-known kind is B. calycina, of which there are many garden forms, including eximea, macrantha, and violacea. They grow well in a compost of sandy loam and peat, and like a stove temperature and a humid atmosphere. They are easily raised from cuttings, and nice bushy flowering plants can be obtained in 5-in. pots in about twelve months.