A nearly related form, which may be regarded as a sub-species, canescens, the grey poplar of the nurseryman, is distinguished from the true abele by its smaller, less deeply cut leaves, which are grey on the upper side, but not so hoary beneath as those of P. alba; the pistil has eight stigma lobes.
Of deciduous trees the sycamore, wych-elm, horse-chestnut, beech, lime, plane and poplar may be used, - the abele or white poplar, Populus alba, being one of the most rapidgrowing of all trees, and, like other poplars, well suited for nursing other choicer subjects; while of evergreens, the holm oak, holly, laurel (both common and Portugal), and such conifers as the Scotch, Weymouth and Austrian pines, with spruce and (South.) silver firs and yews, are suitable.