io6 



MARATTIACEAE 

 _5 L p 



[CH. 



Fig. 400. Sections of stems of Psaroniiis. [A-C and E, after Zeiller: D, 

 after Stenzel, from Seward.] A, Psaronius infarctiis. /"=: peripheral steles ; 

 Z = leaf-traces. B, P. infarclns, longitudinal tangential section through 

 the peripheral region of the stem. C, P. coalescens. D, P. iimsaeformis. 

 £, P. asterolithus, root^. 

 ^ Solms-Laubach described in 1913 a large Brazilian fossil stem named Tietea singularis, of un- 

 certain horizon, and suggested its relationship to the Psaronieae. It seems more probable that it is 

 related rather to Tempskya. Notwithstanding its large size and complicated structure it would not 

 be wise to bring it into the present comparisons, pending more exact information {Zeit. f. Bot. v. 

 (1913). P- 673)- 



