This section is from the book "Commercial Gardening Vol4", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
The Common Almond (A. communis or Prunus Amygdalus) sells well as a standard ornamental tree for flowering in February and March. Besides the ordinary white or rose kind there are several varieties, such as amara, the Bitter Almond; dulcis, the Sweet Almond; macrocarpa, and the double-flowered one (flore pleno) - all worth stocking. All kinds are usually propagated by budding on Plum stocks; but they may also be increased by grafting and layering. See articles on "Cerasus" and "Prunus".
Other Almonds not so well known are nana, a native of South Russia, 2-4 ft. high, with rose-pink flowers in February, March, and April. There are several forms of it. The Silver Almond, orientalis, from Asia Minor, is a more tender species, with a silvery down on the leaves.