214 BRA.CHYPHYLLUM. 



Genus BRACHYPHYLLTJM, Brongniart. 



[Tableau, 1849, p. 69.] 



Brongniart proposed this name for conifers with alternate leaves 

 disposed in a spiral, short, fleshy, and inserted by a broad and 

 rhotnboidal base. Schimper l extends this definition, and speaks 

 of the genus as differing in its characters from all living forms ; 

 he points out the striking resemblance between old branches of 

 BracJiyphyllum, with the leaves in the form of hexagonal or 

 pentagonal cushions, and certain strobili of cycads and conifers. 

 The surface features of a branch from which the leaves have 

 fallen resemble those of Lepidodendron. Saporta ~ further extends 

 Brongniart's definition ; and remarks that probably no genus of 

 conifers has given rise to more confusion and uncertainty than 

 the present genus. It has been compared with several recent 

 genera, but we cannot regard Braclnjphyllum, with its numerous 

 species from various geological horizons, as more than a purely 

 provisional genus, the actual botanical position of which is very 

 uncertain; probably more than one family of Conifer being 

 represented by the forms referred to under this generic name. 

 Schenk 3 has drawn attention to the too comprehensive nature of 

 the genus as used by Saporta, Heer, and others, but does not 

 suggest any more precise definition of the generic characters. 



As Fontaine remarks, there is a striking resemblance between 

 some forms of JZchinostrobus, Bracliyplnjllum, and Palaocypwris. 

 Saporta, in describing the characteristics of Echinostrobus, points 

 out that it differs from Brachyphyllum in having the leaves less 

 thick, more pointed, and less completely adnate to the stem. We 

 may compare both of these fossil genera with certain species of 

 the recent genus Atkrotaxis. The thick fleshy leaves, with their 

 broad rhomboidal bases and spiral arrangement, constitute the 

 leading features of this artificial genus of fossil conifers. 



1 Trait, pal. veg. vol. ii. p. 334. 



2 Pal. FraiHj. vol. iii. p. 310. 



3 Zittel's Handbuch, p. 301. 



