Rumohra adiantiformis var. laciniata is reported as a new variety endemic to the Sierras del Este Eco Region, Southern Uruguay. The new variety inhabits Sierras de Maldonado landscape, growing in shady places of moist hillside forests. It differs from Rumohra adiantiformis var. adiantiformis by the shape and size of the pinnules, lamina, and rachis with a dense and conspicuous indument of capitate glandular hairs, yellowish, with exudate, and by the margins of the rhizome scales with capitate glands. Another two interesting features of this new variety are the furcate or laciniate (cresting) apex of the rachis as well as the pinnae and pinnules, and the faint light-bluish iridescence of the lamina adaxially. These two last features are related to the habitat of these plants that grow in shady places. In this paper, we present a description, illustrations, a distribution map, and discussions about this new taxon as well as a key to identifying the species occurring in Argentina, Southern Brazil, and Uruguay.

Se describe e ilustra Rumohra adiantiformis var. laciniata, una nueva variedad endémica del extremo sur de la Eco Región Sierras del Este en Uruguay. La misma habita en el paisaje Sierras de Maldonado, en zonas semi sombrías del bosque serrano. Se diferencia de Rumohra adiantiformis var. adiantiformis por la forma y tamaño de las pínnulas, lámina y raquis con denso y conspícuo indumento compuesto por tricomas glandulares capitados, bicelulares, amarillentos, con exudado y por márgenes de escamas del rizoma y pecíolos con glándulas capitadas esparcidas. Otras dos características de la nueva variedad son presencia de ápices furcados o laciniados (cristado) visibles en raquis, pinnas y pínnulas, y lámina con tenue iridiscencia celeste en cara adaxial. Estas dos últimas características están relacionadas con el hecho de que estas plantas crecen en lugares sombríos. En este trabajo se presentan descripción, ilustraciones, mapa de distribución y discusión sobre el nuevo taxón, así como una clave para identificar especies presentes en Argentina, Sur de Brasil y Uruguay.

To explore how Asplenium nidus responds to drought stress and to find V-PPase (AVP1) homologous genes of this species, we conducted greenhouse experiments. We measured a series of physiological and biochemical indices after drought treatment and analyzed the expression of AVP1 homologous genes in A. nidus by RT-qPCR. The results indicated that A. nidus can adapt to drought by limiting stomatal conductance, thus inhibiting plant photosynthesis and reducing physiological activities. In addition, A. nidus can also change its osmotic potential by increasing proline content to maintain normal metabolic activities, and prevent the destruction of reactive oxygen species by increasing the activities of superoxide dismutase (SOD) and peroxidase (POD). According to analysis of the relative expression levels of genes, AVP1-2 and AVP1-4 may be the drought-resistant genes of A. nidus. This study lays a foundation for further exploration of the drought tolerance mechanism and drought-resistant genes of A. nidus.

This study aimed to demonstrate that stone walls are habitats for rare ferns and lycophytes in Japan. A survey on 47 Red Data Books (RDBs) published in each prefecture in Japan, revealed the descriptions of 47 fern and lycophyte species (equivalent to 6.5% of all native species of ferns and lycophytes in Japan) designated as near threatened or above in the RDBs and growing on stone walls in Japan. Eleven of these species were listed in the prefectural RDBs as well as in the national RDB of Japan. Overall, 40 species (85.1%) had a preferred original habitat of cliffs or rocky outcrops, and 24 species (51.1%) preferred the forest floor. The high number of identified species that prefer cliffs or rocky outcrops supports the Urban Cliff Hypothesis, which states that man-made structures such as urban buildings and walls serve as alternatives to cliffs, rocky outcrops, or screes as alternative habitat. However, in previous domestic studies that documented fern and lycophyte species growing in established hardscapes in Japan, the most frequently occurring species were mostly weedy or ruderal. As there are few studies on the composition of species growing on stone walls in Japan, more studies must investigate this aspect as well as examining the variation in species composition because of the differences in species pools, climatic conditions, or geological background.

Invasive species are one of the largest threats to vulnerable ecological communities and biodiversity today and are economic burdens across the globe. It is therefore crucial that we understand the origins and the driving forces that promote the establishment, persistence, and spread of these taxa. Polyploidy, or whole genome duplication, has been suggested as a possible factor facilitating the success of invasive taxa, yet is an understudied aspect in invasion biology. Although ferns are often neglected in invasive species inventories, several fern families are overrepresented as naturalized and invasive taxa including the vining ferns in the family Lygodiaceae. The Japanese climbing fern, Lygodium japonicum, is native to eastern Asia, and since its introduction in the early 1900s through the ornamental plant trade, it has rapidly spread throughout the southeastern United States, creating dense thickets that smother native plants and disrupt agricultural pine logging. While previous chromosome counts of L. japonicum suggest that both diploid and tetraploid cytotypes occur in its native range, there are no data for populations in the invaded range to date. Using chromosome counts, flow cytometry, and spore size measurements, we assessed the ploidy of invasive populations of L. japonicum in the state of Florida. We found that L. japonicum is represented by a tetraploid cytotype throughout Florida. Our study is the first to examine the ploidy of invasive L. japonicum populations, although additional work will be needed to determine if this species is tetraploid throughout its invaded range.