Spore Morphology of <i>Platycerium</i> (Polypodiaceae) and Its Implications

The spore characteristics of ferns play an important role in taxonomy; however, comprehensive spore data for most species of the genus <i>Platycerium</i> remain scarce. In this study, spores of <i>Platycerium</i> were examined using light microscopy and scanning electron microscopy. We established the first comprehensive dataset on spore morphology in <i>Platycerium</i>. Based on morphological characteristics, we classified the spores into four distinct types, each described in detail. Spore surface ornamentation proved to be an effective diagnostic feature for <i>Platycerium coronarium</i>, <i>P. madagascariense</i>, <i>P</i>. <i>ridleyi</i>, and <i>P</i>. <i>stemaria</i>. The systematic significance of spore morphology in <i>Platycerium</i> was discussed, while no significant linear correlation was found across <i>Platycerium</i> between spore sizes and genome sizes. Our findings are important for understanding the relationship between spores and ploidy levels in Polypodiaceae and their evolutionary implications.