Spore Morphology Of The Representatives Of The Subfamily Ceratopteridoideae (j. Sm.) R.m. Tryon From The Family Pteridaceae E.d.m. Kirchn. (pteridophyta)
A. V. Vaganov, I. I. Gureyeva, A. A. Kuznetsov, A. I. Shmakov, R. S. Romanets, V. A. KÃÂ¶nig
Scanning electron microscopy (SEM) was used to perform a comparative study for four representatives of the subfamily Ceratopteridoideae (J. Sm.) R.M. Tryon from East Asia: Ceratopteris thalictroides Brongn., C. pteridoides (Hook.) Hieron., Acrostichum aureum Linn., and A. speciosum Willd. The analysis of the external morphology of the representatives of Ceratopteridoideae revealed a strong difference between Ceratopteris and Acrostichum. The external morphology of spores of Ceratopteris and Acrostichum exhibited the features characterizing the family Pteridaceae as a whole: tetrahedral spores with a three-ray laesure, from triangular-roundish to roundish, distinct exosporium with a pronounced surface ornamentation and absence of perisporium, the exosporium surface varying from smooth and rough to that covered with large tubercles and roller-like bulges. The external morphology of spores of Acrostichum is quite simple, although among other representatives of the family Pteridaceae, the spores of Ceratopteris have distinctive features: very large equatorial diameter (106–124 μm); spores are almost roundish; distinct cylindrical folds running parallel to the corners of the spore across its extensive distal surface.