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.
The Date Palm (P. dactylifera) belongs to this genus, but is not a marketable plant. The most valuable species for growers are P. Roebeleni and P. rupicola, both graceful plants with rigid midribs to the loose and arching leaflets. They are grown like the Kentias, and realize from 2s. 6d. to 21s. each, according to size and particular circumstances.