INTRODUCTION 11 



Tetraclinis. 

 Twigs flattened. Leaves scale-like, four-ranked. Cones com- 

 posed of 4 scales. Seeds 2-9 on each scale. 



Widdringtonia , 

 Resembling Callitris, but with the leaves spirally arranged, 

 and numerous seeds to each scale of the cone. 



Actinostrohus. 

 Leaves scale-like, three-ranked. Cone scales C, equal in 

 size, surrounding a central axis, each with one or two winged 

 seeds. 



Callitroj}sis. 

 Closely allied to Callitris, but distinct in the Araucaria like 

 leaves arranged in eight vertical rows and in the cones, which 

 consist of 8 scales in 2 whorls of 4 each. 



Sub-tribe III. Thuinea3. 

 Male and female flowers usually on the same tree. Cone 

 scales woody, truncate and peltate or oblong and joined only at 

 the base. Seeds usually winged. 



Fitzroija. 

 Tree or shrub with three-ranked leaves. Cone solitary, 

 terminal of 2-3 rows of whorled scales, of which only the upper are 

 fertile. Seeds 2-3 winged. 



Diselma. 



Shrub, with opposite scale-like leaves. Cone scales 4, inner 

 pair fertile. Seeds 3 winged. 



Cupressus. 

 Adult leaves, scale-like, appressed. Cones globular or oblong, 

 woody, with peltate scales. Seeds numerous or (section Chamae- 

 cyparis) 2-5 to each scale. 



Thuya. 

 Branch systems flattened, leaves scale-like. Cones with 

 oblong scales which are thickened upwards, the two uppermost 

 pairs fertile, seeds usually winged (not in T. orientalis). 



Libocedrus. 

 Branch system flattened. Leaves scale-like, arranged in 

 decussate pairs. Cones oblong, with 2-6 valvate scales, of 

 which the middle pair alone is fertile. Seed with two unequal 

 wings. 



