A tree up to 120 ft high, pyramidal when young, ultimately assuming, at least in a wild state, the flat-topped shape with horizontally spreading branches, characteristic of the cedar of Lebanon; young shoots downy. Leaves 1⁄2 to 1 in. long, needle-like, stouter than in C. libani, curved towards the tip; varying in colour from green to silvery. Cones 3 in. long, 11⁄2 to 2 in. wide, cylindrical.
Native of Algeria and Morocco on the Atlas Mountains; introduced about 1840. This cedar is very hardy, and is thriving splendidly in various parts of the British Isles. At Kew, on dry, hot soil it grows more quickly and withstands London smoke better than either the Lebanon cedar or the deodar. This species is sometimes difficult to distinguish from the cedar of Lebanon. If large numbers of specimens are examined, they are distinct enough, since average differences then emerge which would not be apparent if only a few examples of each were to be compared. This explains why experts, when confronted by an individual tree, are sometimes in doubt in which species to place it. The Atlas cedar in youth and early maturity is characterised by a stiff habit and erect leader, but in age it assumes the fiat-topped habit wrongly thought to be the perquisite of the cedar of Lebanon. In the Atlas cedar, the shoots are always downy, and more so than those of the Lebanon species. Its cones, too, do not taper above the middle so much.
The following are among the oldest and finest trees measured in recent years: Bowood, Wilts., 132 × 181⁄2 ft (1957); Westonbirt House, Glos., from the original introduction, 102 × 15 ft at 4 ft (1967); Eastnor Castle, Heref., 110 × 163⁄4 ft (1961); Gask House, Perths., 110 × 14 ft (1962); Althorp, Northants, 107 × 131⁄4 ft (1964); Corsham Court, Wilts., 87 × 21 ft, a superb tree (1965); Bodnant, Denbigh. pl, 1876, 110 × 111⁄4 ft (1967).
cv. ‘Aurea’. – Leaves of a yellowish colour. This is only propagated by grafting, and is not so vigorous as seedling trees. There are small examples of this at Little Hall, Kent (pl. 1907), and at Poltimore, Devon, 40-50 ft high.
f. glauca Beissn. – Leaves of a more or less silvery hue; in the finest forms, named argentea, the whole tree is of a beautiful pale, grey-blue colour. Ordinary f. glauca can often be selected among batches of seedlings, and there is every gradation between it and what we regard as the green type – in nature as well as in gardens. This form is as common among the older trees as the green-leaved one. Among the largest recorded are: Bowood, Wilts., 105 × 16 ft (1957); Eastnor Castle, Heref., 102 × 13 ft, from the original introduction (1961); Pampisford, Cambs., 105 × 131⁄4 ft (1959); Bodnant, Denbigh, 105 × 103⁄4 ft (1957); Dropmore, Bucks., pl. 1843, 95 × 13 ft.
f. pendula (Carr.) Rehd. – Leader and branches pendulous. Such forms are known to occur in the wild but the origin of the cultivated trees is unknown. The fine example in the Glasnevin Botanic Garden, with light grey-glaucous leaves, was planted around 1875 (J. P. Fanning in Gard. Chron., 27 July 1957). Two at Tittenhurst, Berks., resemble the Dublin tree in foliage, but are more sharply pendulous.
f. fastigiata (Carr.) Rehd. – Branches ascending. Trees of this character grow at Grayswood Hill, Surrey, 63 × 71⁄4 ft (1965), and Chiltley Place, Liphook, Hants, 55 × 41⁄4 ft (1961). Elwes and Henry mention one at Tortworth, 50 ft high in 1908. The tree described by Carrière (Rev. Hort., 1890, p. 32) was raised by Lalande of Nantes but it is unlikely that any of the trees mentioned, and certainly not the last, are of this origin.