Old World climbing fern, Lygodium microphyllum (Schizeales: Lygodiaceae) invades and negatively impacts natural areas throughout south Florida. Its invasiveness is attributed, in part, to its fast growth rate that allows it to climb rapidly on neighboring vegetation and large reproductive output via aerially distributed spores that are borne on fertile leaves. We conducted a field study to determine the within-plant distribution of the biological control agent, Floracarus perrepae (Acariformes: Eriophyidae), the vertical distributions of fertile leaves, and to evaluate the potential productivity-reproduction tradeoff in L. microphyllum. The 3 m vertical trellises were spatially segregated with galls formed by F. perrepae at the bottom of the trellises and reproduction (i.e., the development of fertile leaves) at the top of the trellises. Galling occurred on 81% of leaves in the bottom stratum versus 40% of leaves in the uppermost stratum of the trellis. Conversely, only 16% of leaves in the bottom stratum versus 76% in the upper stratum were fertile (bore sori). With increasing biomass (i.e., larger plants) fewer reproductive leaves were noted, indicating a trade-off between growth and reproduction. This association was twice as strong in the very largest plants versus the smaller plants. Further, the potential for this productivity-reproduction tradeoff to be impacted by biological control agents may be illustrated by the strong negative correlation between galled leaves and fertile leaves. Lygodium microphyllum thus appears to compensate for mite damage by redirecting energy to regrowth instead of reproduction.

We present the taxonomic revision of genera Dennstaedtia, Microlepia, and Mucura (Dennstaedtiaceae: Dennstaedtioideae) for Brazil. Ten species are recognized: D. aculeata (recently described), D. cicutaria, D. concinna (rescued from synonymy), D. cornuta (with a new circumscription), D. fluminensis (rescued from synonymy), D. obtusifolia (with a new circumscription), Micr. speluncae (naturalized), Muc. dissecta, comb. nov. (rescued from synonymy), Muc. tamandarei, comb. nov. (rescued from synonymy), and Muc. tenera, comb. nov. (rescued from synonymy). Excluded from Brazil are three commonly applied names: D. dissecta, Muc. bipinnata (= D. bipinnata), and Muc. globulifera (= D. globulifera). We present keys to genera and species, comprehensive descriptions, illustrations, maps of distribution, and type data for all species (including the designation of 10 lectotypes).

For many years, the native populations of bird's-nest ferns in Hawai‘i (known as ‘ēkaha) have been referred to as Asplenium nidus. Recent morphological studies on live plants and herbarium vouchers, along with literature review, reveal that the most appropriate name is A. musifolium, which is primarily known from Malesia and Southeast Asia. Furthermore, A. nidus was a horticultural introduction and is now naturalized. This work has also elucidated the need for critical study of bird’s-nest ferns in the Pacific, where several cryptic taxa may be present. Though these ferns do not possess many distinct characteristics, the shape of the midrib and the detail of the scales are diagnostic. We provide an overview of bird’s-nest fern diversity in Hawai‘i, a key to identify native and non-native taxa, recommendations for specimen preparation to improve visibility of diagnostic characters, and a discussion of future research directions.

Parahemionitis arifolia exhibited strong desiccation tolerance enabling it to withstand irregular dry periods in southern Taiwan. Yet, it is poorly understood how desiccation shapes its metabolism. Here, we report metabolic responses to 1- and 3-weeks of dehydration by air drying in this desiccation-tolerant fern. Metabolite profiling and quantitative analysis of water-soluble metabolites in leaf and rhizome extracts were conducted by nuclear magnetic resonance (NMR) spectroscopy. The ¹H NMR metabolite profiles and two dimensional NMR (2D NMR) analysis identified sugars (sucrose, glucose, fructose, and trehalose), amino acids (γ-aminobutyric acid (GABA), alanine, tyrosine, and glutamine), cyclic polyol (quinic acid) and malic acid. Quinic acid was only observed in the leaf samples but was not detected in the rhizome samples. Glucose and fructose contents in rhizomes increased notably with the duration of air-drying. Trehalose content increased in the air-dried rhizomes, though it was detected in much smaller amounts compared to other sugars. The content of GABA increased dramatically in air-dried leaves and rhizomes but was not detected in any fresh samples. The content of sucrose, alanine, and malic acid in leaves and rhizomes increased in response to desiccation. On the contrary, glutamine content in both leaves and rhizomes decreased after air-drying. Based on these results, we conclude that the metabolic response of the fern P. arifolia to desiccation appears to be consistent with most desiccation tolerant plants. The metabolite concentration in rhizomes changed more significantly than in leaves after drying, indicating that rhizomes and leaves have different drought tolerance capabilities.