Ferns are an important part of many ecosystems, especially on islands, but are often overlooked in conservation priorities. Fern propagation can be challenging and requires significant time and resources, especially for rare ferns with limited propagation history. Some fern spores can survive for decades in the soil bank and some dry adapted ferns may store well at room temperatures for several years. Herbaria have been proposed as a source of viable propagules of rare plants for propagation. We explored herbarium specimens as a source of viable spores for conservation of rare and endangered Hawaiian ferns. We examined 156 herbarium specimens for the presence of spores and sampled spores from 50 of them spanning four decades. Germination of spores occurred in 24 specimens representing eight of nine included species within the 15-month experiment. However, gametophytes from spores from only five specimens (10%) representing three species (33%) produced sporophytes during the experiment. While fresh spores provide higher germination success, sporophytes developed from specimens of Pellaea ternifolia collected in 1984, 1989, and 2018, as well as from a specimen of Cyrtomium caryotideum from 2019 and a Doryopteris decora specimen from 2020. This result confirms that herbaria can be a source of dry adapted spores of rare species or populations that may be extinct or otherwise difficult to source. Increased attention on rare fern propagation techniques is critical to successful conservation efforts from both fresh and dried collections such as herbarium specimens.

Plant phenology describes the response of plants to cyclic environmental fluctuations and is a powerful tool in the face of climate change. Most phenological studies in ferns have focused on humid environments, where water is not a limiting factor. However, Mexico has a great diversity of ferns growing in xeric environments (ca. 120 species). We studied the preference for slope aspects and phenological patterns of four of these desiccation-tolerant fern species in a seasonally dry shrubland of central Mexico for 18 months. South-facing rock surfaces and rock tops reached up to 6°C higher air temperatures and up to 24°C higher rock temperatures than North-facing rock surfaces. Myriopteris aurea grew most frequently on the hot rock tops, whereas M. myriophylla and Gaga kaulfussii were most common on cooler northern aspects, and Pellaea ternifolia was found on all lateral rock surfaces. Leaf production and growth of all species were positively correlated with rainfall, but the total leaf number was not seasonal because of their desiccation tolerance. Myriopteris aurea was the first to develop new leaves after the first rainfalls but its leaves dehydrated faster than in the other three species. Myriopteris myriophylla had scaly leaves with the longest life span (7.9 ± 1.1 months), whereas G. kaulfussii had the fastest rehydrating leaves and the highest leaf production during the rainy season. Pellaea ternifolia had glabrous leaves with the shortest life span (4.8 ± 0.2 months). We conclude that each fern species developed a different combination of xeric adaptations to survive under these extreme environmental conditions.

This review updates the basic biology of moonwort ferns, genus Botrychium, (Ophioglossaceae). It is intended to provide background to readers of this issue and to alleviate the need for repeating this information by subsequent authors. At present, 38 species of Botrychium have been described, with occurrences worldwide in a diverse range of habitats, most commonly in meadows dominated by herbaceous perennial flowering plants that are the alternative host of the mycorrhizal fungi that support belowground growth of Botrychium. The genus produces small aboveground leaves that produce sporangia. Leaves of individual plants may remain dormant belowground in some years. Individual plants may live for decades. Spores germinate belowground and, following colonization by a mycorrhizal fungus, produce belowground bisexual gametophytes that have a high probability of intragametophytic selfing, commonly resulting in populations with low allelic variability. Because of their small size and reduced morphological complexity, Botrychium species have often been referred to as cryptic species. Though difficult to identify, genetic analysis has shown species distinction to be equal to that of non-cryptic species, and has allowed recognition of morphological characteristic of each taxon.

Fern gametophytes are an often-overlooked part of field studies on ferns due to the challenge of finding material and the difficulty of identifying wild-collected plants. Most existing gametophyte descriptions are derived from lab-reared plants and while it is thought that many of the morphological features are similar under both conditions, we still have a poor understanding of in situ morphology for most taxa. The goal of this work was to document a set of morphological observations from the gametophytes of six different species collected in situ. We discovered identifiable gametophyte populations of Elaphoglossum latifolium, Hymenophyllum myriocarpoum, Lomariopsis maxonii, Polypodium dulce, Polytaenium cajenense, and Sticherus bifidus during the 2022 OTS Tropical Ferns and Lycophytes course in Costa Rica. Gametophytes were collected in the field, observed, and photographed using stereo and compound microscopy. This work represents the first detailed description for these species' gametophytes from field collections and offers insights into their natural morphology.