PINACE^ 501 



many centuries, and is reputed to be the " citrus wood " of the 

 ancient Romans, who esteemed it above all others for roofing 

 temples, and for tables and cabinets. It is still in demand for 

 fancy cabinet-work, and various articles manufactured from the 

 wood are to be seen in the Museums at Kew. A hard resin known 

 as " Sandarac " exudes from the trunks and large quantities are 

 exported annually from N. Africa, mostly to Britain, where it 

 is used for varnish- making. For centuries it has been one of the 

 stock resins for pale spirit varnishes. 



T. articulata is a useful tree for hot and dry countries, and 

 steps are being taken by the French Forest Service to extend its 

 sphere of usefulness in their N. African colonies. It is doubt- 

 fully hardy even in the milder parts of Britain. 



THUYA, Linnseus. 

 Arbor-vit^. 



Biota, EncUicher ; Thiijopsis, Siebold ; Tluija. 



Evergreen trees and shrubs belonging to the tribe Cupressineae. 

 Seven species, natives of China, Japan, Formosa, and N. 

 America, are known. They form trees of shapely pyramidal 

 outline. Bark thin, fissured on old trees, outer bark scaling 

 in patches of irregular shape ; inner bark fibrous. Branches hori- 

 zontal or ascending. Branchlets slender, tough, flexible, divided 

 near the apex into fine spray, smaller branchlets deciduous 

 with the leaves after several seasons. Buds hidden by leaves. 

 Leaves small, scale-like, overlapping, in 4 ranks of 2 opposite sets, 

 the upper and lower ranks flattened or grooved, the side ranks 

 rounded or keeled ; those on the main axis djdng and remaining 

 in position for several years afterwards, those on lateral branch- 

 lets smaller and falling with the shoots. Leaves of seedling plants 

 and of some varieties needle-like and spirally arranged. Male 

 and female flowers on different branchlets of the same tree, opening 

 in March and April. Male flowers reddish, cylindrical or globular, 

 from branchlets near the base of the shoot, composed of 3-6 

 pairs of stamens. Female flowers cone-Uke, arising from short 

 terminal branchlets, very small, green or purple-tinged, com- 

 posed of a few opposite pairs of leaf -like scales. Cones solitary, 

 |-§ in. long, made up of 3-10 pairs of scales, which are in most 

 species thin and flexible. Seeds small, winged or wingless, 2-3 

 or 5 on each fertile scale, usually 2-3 pairs fertile. 

 The species are divided into three sections : — 

 1. EuTHTJYA. — Branches horizontal, branchlets flat, more or 

 less in the same plane. Cones conical, with thin, tapering scales, 

 the points turning outwards when mature, green when young, 



