Microbial endophytes are integral factors in plant evolution, ecology, and physiology. However, the endophyte communities across all major plant lineages have yet to be characterized, and data are particularly scarce for lycophytes. Here we used a culture-based approach to survey the diversity of endophytic bacteria in five sympatric Lycopodiaceae species in central New York. The most notable endophyte isolated from this study is a bacterial species Allobranchiibius huperziae, which was only recently described from the roots of Huperzia serrata in China. The fact that the same endophyte was also found in our North American samples suggest a possible specific association with Lycopodiaceae species. The data and cultures from this study provide an important foundation for future metagenomic and functional studies to characterize better the diversity and significance of plant endophytes.

In southeast Florida an association between the shoestring fern (Vittaria lineata) and the pantropical moss Octoblepharum albidum is conspicuous on cabbage palm (Sabal palmetto) trunks. As determined from quadrat studies, for maturing sporophytes, but not for gametophytes and tiny sporophytes, the frequency of association exceeded that expected by chance. The positive association suggests the moss facilitates the fern sporophytes. Based on a literature review and on new observations, the structure of the moss and its intimate relationship with V. lineata roots is consistent with the moss serving as a water-retentive “mulch” for V. lineata. In different habitats V. lineata can associate alternatively with the moss Syrrhopodon incompletus, and it sometimes grows on decaying petiole-base remnants or in petiole-base axils with no moss association. The only vascular epiphyte competing with V. lineata locally is the fern Phlebodium aureum. The lengths of its leaf blades, but not those of V. lineata, correlate with the lengths of immediately adjacent S. palmetto petiole-stumps. Phlebodium aureum is prominent where the stumps are long, whereas V. lineata dominates in trunk regions having no or small petiole-stumps, where it usually associates with O. albidum.

The ferns of Adiantum Series Gravesiana (Pteridaceae) consist of species that occur exclusively on Danxia (A. juxtapositum) and Karst (A. mariesii, A. longzhouensis, A. dentatum, A. obovatum, and A. gravesii) landforms. We cultured representatives of these six species from 20 different populations on both agar and soil to investigate and compare their gametophyte development. All species had the Vittaria-type pattern of spore germination except A. obovatum, for which we missed the best time to observe this developmental phase. However, two different patterns of subsequent development were observed: the Adiantum-type (i.e., naked, cordate mature gametophyte thallus) in A. mariesii, A. longzhouensis, A. juxtapositum, and A. gravesii and the Kaulinia-type (i.e., naked, ribbon-shaped mature gametophyte thallus) in A. dentatum and A. obovatum. All populations from A. juxtapositum and A. gravesii possess the same Adiantum-type, suggesting that Karst and Danxia soils were not the main factor causing the differences in gametophyte development. The Kaulinia-type adult thallus has not been observed previously in Adiantum and may be an adaptive strategy for survival within the relatively harsh micro-habitats experienced by A. dentatum and A. obovatum compared to other members of this series.

Menisciopsis wailele (Thelypteridaceae) is a single-island endemic fern species restricted to the Hawaiian island of Kaua‘i. All observations indicate it is an obligate rheophyte, preferring sites of fast-moving water along concave walls of remote streams and waterfall edges. This paper presents data on its morphology, evolution, taxonomy, distribution, abundance, and ecological characteristics. Based on phylogenetic and geographic evidence, the ancestor of the Hawaiian species of Menisciopsis may have dispersed from the mountains of continental East Asia. A formal IUCN assessment of the species has been completed and is reported here as Critically Endangered (CR B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)).