Trophopods are modified stipe bases that function as starch-storage organs in a wide variety of mainly temperate ferns. Ever since they were first observed, the presence of trophopods has been explained by reference to seasonality and they have been assumed to provide nutrition for the rapidly expanding fern leaves in spring. We present the results of an analysis of the annual variation in starch content in Matteuccia struthiopteris (L.) Todaro, cultivated in the Leiden botanical garden. Our results show a distinct seasonal variation in starch content, suggesting that the presence of trophopods is indeed functionally linked to seasonality, but we do not find a decrease in starch content corresponding to the period of leaf expansion that would clearly link the depletion of stored starch to the expansion of new leaves.

Gametophytes of epiphytic and epipetric pteridophytes occur frequently in bryophyte colonies; however, little is known about the influence of bryophytes on pteridophyte establishment. In the present study, we describe how the spore-holding capacity of bryophyte colonies contributes to the retention of pteridophyte spores in a vertical environment. Lycophytes did not grow at the sampling site; hence, we used Lycopodium spores to distinguish from any other pteridophyte spores that might have already been present in the wild. We dispersed aliquots of approximately 500,000 spores on vertically suspended bryophyte (both mosses and liverworts) colonies (5 cm × 5 cm) attached to ceramic plates. The bryophyte colonies included ten species (seven mosses and three liverworts), which have different characteristics in colony height, leaf length, and dry weight. Mudstone blocks and ceramic plates were used as control surfaces (5 cm × 5 cm). After simulated rainfall, we counted the number of spores retained in the colonies and controls. We found that the bryophyte colonies retained a significantly higher percentage of Lycopodium spores (90.7±7.4%) than the controls (ceramic plate: 7.5±20.9%; mudstone: 39.7±20.6%). The average values of retained spores within the bryophyte colonies correlated with their logarithmic values of dry weight per square centimeter (R² = 0.62, P < 0.05). Leaf thickness and stem diameter were slightly different across species. Thus, dry weight value of bryophyte colony per unit area is very likely a simple function of number of stem-and-leaf units, which correlate closely with the surface area. Bryophyte colonies that have high surface area on which pteridophyte spores might be retained within a colony might provide a suitable environment for spore adherence in epiphytic and epipetric habitats.

The study of the pteridophytes of the Guiana Shield and the writing of the Flora of the Guianas led to the discovery that, taxonomically, a few combinations were not yet established for certain taxa. Accordingly, new combinations are proposed for two subspecies of Hymenophyllaceae (Didymoglossum punctatum subsp. labiatum and D. punctatum subsp. sphenoides), two varieties of Pteridaceae (Jamesonia paucifolia var. neblinae and J. paucifolia var. steyermarkii) and one species of Thelypteridaceae (Amauropelta demerarana).

Three species of the genus Cyathea from the sandstone areas of the Amotape-Huancabamba zone are described as new to science: Cyathea abrapatriciana and C. oreopteroides from northern Peru and C. chimaera from southern Ecuador. They are illustrated and discussed regarding their biogeography and putative relationships.

We present a taxonomic treatment of the genus Oleandra in the Brazilian Atlantic Forest. Five endemic species and one putative hybrid are recognized: O. australis, sp. nov. (endemic to the state of Paraná), O. baetae (endemic to state of Minas Gerais), O. brasiliana, sp. nov. (widespread along the Brazilian Atlantic Forest), O. hirta (endemic to the state of Rio de Janeiro), O. quartziticola, sp. nov. (endemic to the state of Espírito Santo), and O. baetae × O. brasiliana (from places of sympatry). The widely used name “Oleandra articulata” does not apply to the Brazilian Atlantic Forest species. All species are described, illustrated, and mapped.

Diplazium laffanianum was last collected from its natural habitat in Bermuda in 1905. Now the species is considered extinct in the wild as it exists only in greenhouses, tissue cultures, and as a few young reintroduced sporophytes. For the last 13 years, a collaborative team of researchers from the Government of Bermuda and the Lab for Rare & Endangered Plants at Omaha's Henry Doorly Zoo in Nebraska, USA has been working to bring this species back from the brink of extinction. In this project, we developed propagation methods for D. laffanianum, and we studied molecular and morphological characters to determine the phylogenetic placement of D. laffanianum. We sequenced plastid DNA from D. laffanianum using high-throughput sequencing, downloaded six plastid markers (atpA, atpB, matK, rbcL, rps rps4-trnS, and trnL intron trnL-F) from GenBank for 21 Diplazium and outgroup taxa, and inferred a phylogeny. We examined 185 collections of five Diplazium species closely related to D. laffanianum, and we scored 15 morphological characters to test whether D. laffanianum is a distinct species. The phylogeny placed D. laffanianum in the D. cristatum group, suggesting a Neotropical ancestor, and two morphological characters distinguished D. laffanianum from close relatives. Our results provide evidence for the phylogenetic placement of D. laffanianum, and we are actively propagating and reintroducing individuals to the wild, aiding conservation of the species.