The plants mostly known under this name in nurseries are referred to under the genus Abies in this work (see p. 59), and, with strange perversity, the Piceas proper are known as Abies in nurseries. The most important kinds are Alcockiana, a beautiful pyramidal Japanese tree, 90-120 ft. high; alba, 50-170 ft., North America, the White Spruce, valuable for damp situations; ajanensis, 70-80 ft., Japan; Engelmanni, 80-150 ft., Rocky Mountains, with a fine variety, glauca. P. excelsa, the Common Norway Spruce or Burgundy Pitch Pine of North Europe, 100-120 ft. high, supplies the white deal of commerce. It is well known in a small state as the popular Christmas Tree. There are numerous varieties, amongst the best being Clanbrassiliana, a dense bush, 2-3 ft. high; aurea, shoots tipped with yellow; pygmwa (nana), a pyramidal shrub about 1 ft. high. P. Morinda (Smithiana), from North India, 80-120 ft., has an elegant drooping habit. P. nigra, the Black North American Spruce, 50-70 ft., a quick-growing tree with blue-green foliage, has a dwarf variety, pumila, 3-4 ft., and a red-barked one, rubra. P. orientalis, from the Caucasus, is a somewhat dense-growing Spruce, with a golden form, aurea, and a dwarf one, pygmoea. The Tiger-tail Spruce (A. polita), a handsome Japanese conifer with yellow-barked shoots, makes a splendid lawn tree. The American Blue Spruce (P. pungens) grows up to 160 ft., has rich orange-coloured bark, and its varieties, argentea, with silvery hues, and glauca, blue green, are charming lawn plants, but even they are inferior in beauty to Kosteri, a splendid one with conspicuous foliage. It is usually grafted on stocks of the type. The Sitka Spruce (P. sitch-ensis, Abies Menziesi) grows up to 200 ft. in California, and has been largely planted in Britain. It is valuable for hilly districts and for forest work in general.