480 CYCADOPHYTA [CH. 



BUCKLANDIA. Presl. 



Bucklandia was proposed by Presl^ for a plant described by 

 Mantell^ from tbe Wealden of Tilgate Forest and compared by 

 him to the Euphorbiaceae and arborescent Ferns; the same 

 generic name was given by Robert Brown in 1832 to a recent 

 member of the Hamamelidaceae. Stokes and Webb* referred 

 the same fossil to Clathraria, a name applied by Brongniart* to 

 certain types of Sigillarian stems and afterwards adopted by him 

 for the Tilgate Forest species, C. Lyelli. Presl 'with remarkable 

 discrimination' recognised the Cycadean nature of the specimen. 

 Carruthers^ in his definition of Bucklandia includes a statement 

 as to the nature of the carpellary leaves and suggests that a cone 

 associated with the stems may be a staminate strobilus: the 

 cone is undoubtedly a megastrobilus of an Araucarian plant and 

 there is no evidence with regard to the nature of either the male 

 or female reproductive organs in the material that he describes 

 though, as already pointed out, there are reasons for believing 

 that Williamsonia flowers were borne on branches of Bucklandia 

 stems. The flowering shoots were not short and intercalated 

 among the petiole- bases as in Cycadeoidea with the strobih barely 

 projecting beyond the surface of the leaf-base armour, but they 

 formed comparatively long branches, sometimes forked, at the 

 apex of the main stem (cf. figs. 541 — 543). 



Bucklandia is usually represented by casts, from Rhaetic to 

 Lower Cretaceous strata, differing from Cycadeoidea in the absence 

 of numerous axillary short fertile shoots, in the more slender form 

 and greater length of the stems, and in the less uniform size of 

 the persistent leaf-bases which assume various forms. Some of 

 the specimens reach a length of 4 feet and afford evidence of 

 occasional branching: the surface is covered with leaf-bases 

 preserved as imbricate, broad, and obtuse or truncate scales 

 (fig. 575), or as slightly convex polygonal areas in some cases 

 showing k tendency towards an irregular zonal arrangement of 

 larger and smaller leaf-bases (fig. 576). Within the armour of 

 leaf-bases there may be a cast of the large pith the surface-features 



1 Presl in Sternberg (25) A. p. xxxiii. 2 Mantell (27). 



' Stokes and Webb (24). « Brongniart (22) A. p. 209; (28) A. p. 128. 



5 Carruthers (70) p. 682. 



