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THE GENUS HTHROTAXIS. 



I. HISTORICAL. 



This genus was established by D. Don in 1839. The orthography of the name 

 has varied under different botanists, Arthrotaxis being used by some; the original 

 spelling of Don is, however, retained here, being taken from ddp6o<;, — crowded. 

 The known species, numbering three, are small trees reaching a maximum height 

 of 100 feet, and are all indigenous to Tasmania. 



According to Masters some closely allied fossil forms have been recorded 

 from the Upper Oolite, Solenhofen (Renault); also at Stonefield and Scarborough. 



II. SYSTEMATIC. 



Leaves small, homomorphic, decussate or in close spires, appressed or 

 Spreading. Male amentum terminal, catkin-like; microsporophylls spirally arranged, 

 imbricate, shortly attached, scale or leaf-like expansion, oblong, sagittate and 

 peltate, bearing two-celled sporangia; the pollen cells are globose or three-sided, 

 with two or three bands. Female amentum is composed of spirally arranged 

 imbricate macrosporophylls, bearing from three to six pendulous ovules. 



Fruit cones terminal, sessile, small, globular, composed of woody scales 

 wedge-shaped at the base, thickened upwards, dilated at the apex, below which 

 is a dorsal point. Seeds few under each scale, ovate, compressed, with a 

 transverse hilum and two longitudinal wings, the integument being crustaceous. 

 The cotyledons number two. 



The following are given as separate species, being generally so regarded, 

 but as the differences are mostly in the size and disposition of the leaves, we are 

 of opinion that they may be one species, the variability being perhaps due to 

 environment and climatic conditions. The timbers are practically identical. 



1. Athrotaxis sclaginoides. 



Don in Trans. Linn. Soc. XVII I, 172, t. 14 ; also figured in Hook. 



Ic. PI. t. 574. 



"KING WILLIAM PINE." 



Habitat. 

 This tree is found in the neighbourhood of Williamsford, Tasmania. 



