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.
Graceful dwarf perennials with ornamental bristly leaves often highly coloured with rose, brown, or purple. They grow in moist peat and loam, and are useful for the rock garden or border. Propagation is effected by division and seeds, and plants sell at anything from 3d. to 6d. each. The best kinds are alpinum, diphyllum, macranthum or grandiflorum, Musschianum, pinnatum, purpureum, rubrum Perralderianum - all of which grow about 1 ft. high in dense masses.