l] elatocladus 429 



ELATOCLADUS. Halle. 



This genus was founded with a view to reduce the 'present 

 state of intolerable confusion in the classification of the Conifers^.' 

 Halle expresses the opinion, with which most botanists cannot but 

 agree, that sterile shoots of Conifers should not be described under 

 generic names which imply the possession of a certain type of 

 cone. The occurrence of foliage-shoots of similar or even identical 

 habit in certain recent genera possessing distinct types of repro- 

 ductive shoots serves to emphasise the unscientific character of 

 the too common practice of assigning fossils to genera distinguished 

 by a particular form of cone even though the specimens in question 

 afEord no evidence of the nature of the fertile branches. The 

 generic name Taxites has been widely employed for dorsiventral 

 branch-fragments bearing linear leaves with a pseudo-distichous 

 arrangement as in the recent Taxus, but notwithstanding the 

 employment of Taxites by authors who do not intend to convey 

 the impression of relationship to Taxus, it is preferable to reserve 

 Taxites for specimens which there are reasonable grounds for 

 believing to be related to the Taxeae. Halle insists that it is 

 undesirable to use one name for dorsiventral shoots and another 

 for shoots with spirally disposed leaves, as fossil forms are known, 

 e.g. Stachyotaxus elegans, Nathorst, in which both types occur on 

 the same plant. Similar cases of dimorphism are well illustrated 

 by Dacrydium and other recent Conifers (cf. fig. 708, p. 160). 

 Entocladus is proposed for sterile coniferous branches of the radial 

 or dorsiventral type, 'which do not show any characters that 

 permit them to be included in one of the genera instituted for 

 more pecuhar forms.' 



The name serves a useful purpose for sterile shoots which it 

 has been the custom to include in Taxites and for types such as 

 Elatocladus heterophylla Halle, which bear both distichous, linear 

 leaves and crowded scale-like leaves similar to those of Brachy- 

 phyllum and some forms referred to Pagiophyllum. It is, however, 

 desirable to retain Brachyphyllum and Pagiophyllum for sterile 

 shoots exhibiting no well marked dimorphism and bearing fleshy 

 appressed leaves and four-sided falcate leaves respectively. Used 



1 HaUe (13^) p. 82. iXdrri, Pine or Fir; kMSos, shoot. 



