Polevova, S.V. Sporoderm ultrastructure of Oedipodium griffithianum (Oedipodiopsida, Bryophyta)

Arctoa (2015) 24: 419-430

doi: 10.15298/arctoa.24.34

Spores of Oedipodium griffithianum are studied under SEM and TEM, revealing a unique combination of characters: distinct trilete laesura, distal surface densely covered by club-shaped papillae often fused by their distal parts, perine mostly eroded and fallen off in the mature spores, and layer between exine and intine strongly variable in size and texture between distal and proximal hemisphere. This layer is homogeneous or occasionally totally absent at distal pole, lamellose in equatorial region in sections of fully developed spores, while indistinctly lamellose to homogeneous in a slightly premature spores; in the proximal hemisphere and in laesura it is thick and has complex structure. In somewhat premature spores an electron dense perine is observed upon exine, but it seems to easily fall off during spore maturation, so fully mature spores almost lack perine like in Bruchia brevifolia. Oedipodium is similar to Sphagnopsida in distinct laesura, unstable perine and complex multilaminate innermost layer of exine, a remnant of tripartite lamella.