July, 1921.] OOVBA .— GAPS OF STELE IN POLYPODJACEAE. HJ 



P. Standishii Chr. ; Aspidium viridescens MiQ. (ryomen-sliida) 

 P. varium Pr. ; Aspidium varium Sw. (itachi-shida) 

 Woodwardia radicans Sw. var, orientalis Sw. ; W. orientalis Sw. 



(ko-mochi-shida) 

 All these materials were examined in fresh condition. From the 

 series of free-hand sections a solid model of the stele was constructed 

 in order to find the relation of foliar traces and gaps. For the 

 sake of clearness in demonstration, however, the stelar model was 

 developed diagramatically in such a way that the left side of the 

 figure corresponds the upper side or the part near the apex of the 

 rhizome. 



Though the determination of phyllotaxy from the external ap- 

 pearance is difficult, it may be done comparatively easily from the 

 arrangement of foliar gaps. Frequently there will be cases with 

 twisted rhizomes, but in the present descriptions and diagramatic 

 figures they are described and figured, for the sake of clearness, as 

 if they were not twisted. Though the anatomical structure of meri- 

 steles was also studied, it was omitted here, for it is not the object 

 of the present paper to describe it in detail. 



Observations. 



Microlepia pilosella (Hk.) Moore. Slender creeping rhizome with 

 pretty long internodes. The structure was described by Gwynne- 

 Vaughan^^ as Davallia birsuta. The result of the present research 

 agrees with his observation. Insertion part of a leaf-trace is parallel 

 to the axis of the rhizome, and a gap is situated lateral to the trace. 

 Leaves are arranged actually in two alternating rows on the upper 

 side of the creeping rhizome. The stele is typically solenostelic, 

 because gaps do not overlap. 



Microlepia Wiefordi Moore. The external and internal construc- 

 tion is quite similar to the preceding species, and it is not necessary 

 to describe further. 



Microlepia marginata (Hoett.) Chr. Though the configuration 

 is far larger and the branching occurs very often, the construction 

 is equivalent to the preceding. Gwynne-Yaughan^^ also described 

 correctly as Davallia marginalis. 



Adiantum pedatum L. Creeping rhizome with pretty crowded 

 leaves, rarely with long internodes. Each foliar trace and gap are 



Ij GwYNNE-VAuanAN, I.e. ^03. 



