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.
This is a genus of bulbous plants, natives of South Africa, with fibrous-coated corms, and long spikes of lovely flowers excellent for cutting purposes. Unfortunately they can only be grown in the open air in the mildest parts of the kingdom, but market growers in the south and west of England, and in most parts of Ireland, should be able to reap fair results from their growth. There are several fine species, of which crateroides or speciosa, with brilliant crimson flowers, and viridiflora, with deep sea-green flowers with a black blotch in the centre, are the most noteworthy. The hybrid forms, however, are somewhat hardier, and have many charming shades of colour from white to pink, cerise, orange yellow, magenta purple, etc. Bulbs or corms can be bought wholesale for 20s. to 70s. per 1000 according to variety, but growers' mixtures (good enough for market work) are obtainable for about 5s. per 1000 bulbs.