An evergreen tree sometimes 150 to nearly 200 ft high, with a trunk girthing over 60 ft; branches often swollen at their junction with the main stem. Branchlets arranged in horizontal fashion, the ultimate divisions flat, about 1⁄16 in. wide. Leaves dull green on both surfaces, closely appressed to the stem in adult trees, about 1⁄16 in. long, pointed; in young trees they are only appressed at the base, the more slender sharper points being quite free; the side leaves are keeled and boat-shaped, the front ones ovate and shorter. Cones 1⁄3 in. wide, ellipsoid, with about ten scales; seeds with narrow wings.
Native of Formosa; first introduced by means of a single plant in 1910 by Admiral Sir Lewis Clinton-Baker to his brother’s collection at Bayfordbury, Herts. The following year a quantity of seeds were received at Bayfordbury, from which a large number of plants were raised. The Formosan cypress may be regarded as one of the vegetable wonders of the world. Although considerably less in stature than the sequoias of California, it almost equals them in size of trunk, for trees girthing over 70 ft have been recorded. It appears to be most nearly related to C. pisifera, which differs in its globose cones, broadly winged seeds, and well-defined whitish patches beneath the sprays of foliage. H. J. Elwes visited Formosa in 1912 and, as indicating the extraordinary durability of the timber, mentions that he saw old, prostrate trunks of this cypress with trees growing on them that were 200 to 300 years old. He estimated the age of the largest trees as between 1,200 and 1,500 years.
The Formosan cypress is rather tender, at least when young. It would probably thrive best in a sheltered location in the milder and rainier parts of the country, wherever the summers are not too cool, but it is rather doubtful whether even there it will ever make a good tree. Specimens from the 1911 introduction now average about 38 ft in height and 31⁄2 ft in girth and are to be found in the following collections: Nymans, Borde Hill, Tilgate, Wakehurst Place and Warnham Court, all in Sussex; Bicton, Devon; Stourhead, Wilts.; Hergest Croft, Heref.; and at Kew. In Eire there are examples at Fota and on Garinish Island, Co. Cork, and at Mount Usher, Co. Wicklow.