236 THUIA DOLABKATA. 



we have thence three sections distinguished by the structure of the 

 fruit :- 



EUTHUIA, strobiles pendulous, scales not thickening upwards and 



bearing two three winged seeds. T. occidentalis, T. yigantea and 



T. japonica. 



BIOTA, strobiles erect with thickened scales prolonged at the apex 



into a curved or horn-like process, and bearing two wingless seeds. 



T. orientalis. 



THUIOPSIS, strobiles sub-pendulous, with scales much thickened at the 



apex and bearing four five winged seeds. T. dolabrata. 

 All the Thuias are hardy in Great Britain ; they are among the 

 most useful of Conifers on account of the numerous purposes for 

 which they may be planted and the variety of soils and situations in 

 which they will grow, but in these respects the following circumstances 

 should be noted : The American species mostly inhabit low-lying 

 moist situations as the banks of rivers and streams and around 

 lakes ; the Japanese species are sub-alpine, but always where the 

 annual rainfall is almost double that of the greater part of England. 

 T. orientalis is cultivated in China and Japan under many varied 

 conditions of climate and environment, but thrives best where the 

 climate is most humid. These facts go far to explain how it is 

 that in retentive loams with a naturally drained subsoil, or where 

 the supply of moisture at the roots is not intermittent during the 

 growing season, the Thuias attain their best development, form 

 handsome specimens for the decoration of the garden and retain 

 their foliage and leafy branchlet systems longest. 



Thuia dolabrata. 



A tree or undershrub according to situation or altitude ; in its 

 arborescent form occasionally rising to a height of 40 50 feet with 

 a relatively slender trunk covered with light red bark. In Great 

 Britain it usually has the aspect of a dense pile of foliage of broadly 

 conical outline, the trunk covered with chocolate-brown bark peeling off 

 in longitudinal shreds. Primary branches close-set in pseudo-whorls or 

 scattered, slender, spreading horizontally or depressed by the weight of 

 their appendages ; secondary branches distichous, ramified at the 

 extremities into the frondose branchlet systems common throughout the 

 genus. Leaves persistent five seven years, four-ranked in decussate 

 pairs; on the principal axis ovate, obtuse, free at the apex ; the 

 dorsiventral pair on the lateral growths, obovate-oblong, keeled and 

 concrescent, except at the apex, the lateral pair dolabriform (hatchet- 

 shaped) acute ; yellowish green on the upper side of the branchlets 

 where fully exposed to direct sunlight ; darker with a white stomatiferous 

 band on the under side. Staminate flowers about 0'25 inch long, 

 bearing 12 20 anthers with orbicular imbricated connectives in decussate 

 pairs. Strobiles broadly ovoid, 0*75 inch long, composed of eight ten 

 ligneous, imbricated, rhomboidal scales thickened at the apical end, each 

 bearing five winged seeds or less bv abortion. 



