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 large genus of bulbous plants from tropical and subtropical parts of the world, having large strap-like leaves and bell-shaped flowers borne in umbels on top of stout fleshy scapes. The tropical species like stove treatment, but some kinds are almost hardy, such as C. Moorei, C. Powelli, C. Johnstoni and C. longifolium. The trade is small, and is confined to nurserymen. The plants flourish in well-drained loamy soil, and are increased by seeds and offsets.