Ceiba is a genus of tree species with a predominantly neotropical distribution which, in general, are readily recognized in the landscape in the vegetative stage by their large trunk with prickles, commonly ventricose (swollen). Some Ceiba species have overlapping geographical distributions, such as C. speciosa and C. pubiflora. These species have quite uniform vegetative features, making it difficult to differentiate them when they are not in flowering. Here, we examined the leaflets anatomical features of the two species in order to distinguish them while in the vegetative phase. Fully expanded leaves were collected, fixed, embedded in paraffin and cross-sections were made from the leaflets midvein, margin and intercostal region. Ceiba speciosa has hypostomatic leaflets, with continuous biseriate epidermis along the adaxial face, rectilinear margin with a vascular bundle at the end of the margin while Ceiba pubiflora has amphistomatic leaflets, with interrupted biseriate epidermis along the adaxial face and curved margin on the abaxial face. These taxonomically important anatomical features of C. speciosa and C. pubiflora leaflets have provided additional characters good for distinguishing the species especially when they are in the vegetative phase; and therefore updates the existing accounts of the characters useful for the taxonomy of Malvaceae.

In the USA, road salt usage in urban areas has increased since the 1950’s. In the greater Chicago area over 175,000 tons of salt are applied every year. The salt runoff from this application has the potential to negatively impact nearby plants and alter native plant communities. We evaluated how varying salt concentrations affect overall germination, germination probability, and multiple metrics of germination speed for seeds from five source populations of <i>Thuja occidentalis</i>. Two populations in a native forested fen system are susceptible to salt runoff from the Illinois Tollway. We found that increased salt concentrations decreased both the probability of germination and overall germination, and increased the time to germination. Seeds from the two natural populations performed poorly compared to the other populations. Salt pollution impacts the health and survival of adult trees, and may also inhibit the reproduction and recruitment of <i>T. occidentalis</i>. Reduction of salt pollution is necessary to maintain the long-term survival and persistence of this species, other sensitive species, and native fen habitats.

Associations between bryophytes and dinitrogen (N2)-fixing bacteria are a significant source of exogenous N in unmanaged boreal and possibly temperate ecosystems. However, the extent to which biological N2-fixation (BNF) applies to the boreal-temperate ecotone remains elusive. The current focus on common species limits our understanding of BNF at the community level. Our objective was to characterize the presence of cyanobacteria and BNF activity associated with bryophytes in the coastal forests of Fundy National Park (New Brunswick, Canada). In 2021, we harvested three liverwort and 11 moss species from two sites (71 samples) and measured environmental covariates (e.g., canopy composition, soil pH). We used stable isotope incubations with 15N2 gas in growth chambers to quantify potential BNF activity and used phycocyanin extractions as a cyanobacteria abundance proxy. Many species presented detectable BNF rates, which were similar to or higher than those of well-studied feather mosses. These included species that have rarely been found to contribute to BNF. While cyanobacteria were present on most samples, we found no positive association between abundance and BNF. Our findings are among the first records for bryophyte-associated BNF in the boreal-temperate ecotone of eastern Canada and offer insights into the potential role of this process in N cycling in coastal conifer-dominated forests.

The tiny terrestrial orchids (plant height less than 8 cm) in the genus Corybas dependent on mycorrhizal fungal (OMF) partners for seed germination and seedling development. The OMF community of the Corybas remains poorly understood, although the relevant knowledge is very important for in situ and ex situ conservation of these orchids. In this study, we characterized OMF richness and compositions of three helmet-orchid species, i.e., Corybas geminigibbus, C. himalaicus, and C. shanlinshiensis, from their natural habitats by using Illumina sequencing of the ITS2 region. We found that fungal colonization was restricted in the rhizomes of the helmet-orchids instead of their tuberoids, and serendipitoid fungi were predominant while tulasnelloid were absent in the three investigated Corybas species regardless of their altitude. The three Corybas species shared 27 serendipitoid operational taxonomic units (OTUs) that are different to those of their related orchids, the genera of Cyrtostylis and Stigmatodactylus. Corybas shanlinshiensis alone had a range of ectomycorrhizal fungi (mainly russuloid and thelephoroid) broader than C. himalaicus and C. shanlinshiensis. Our study provides new information about terrestrial orchid-fungi associations and may further contribute to orchid conservation.

Carex dianae Steud. is an endemic sedge of St Helena, an isolated island in the South Atlantic. Our study provides the first molecular sequence data for this taxon. We generated sequence data for plastid matK and trnK regions and nuclear ITS and ETS regions to determine the placement of C. dianae in the broader Carex phylogeny. The placement of C. dianae falls within Carex sect. Spirostachyae Drejer, and it is sister to a clade including Carex clavata Thunb., Carex aethiopica Schkuhr (both from the Cape region of S. Africa), and Carex gunniana Boott (southern Australia). The existence of three divergent nucleotype groups and two plastotypes is revealed from genetic variation within C. dianae. The results suggest that the ancestor of C. dianae likely originated in the Cape region of South Africa, followed by transoceanic dispersal to St Helena estimated at 4.4 - 4.9 Mya, likely by a bird vector. The most divergent population is that on an isolated hill known as “The Barn” which may represent a distinct taxon. The existence of highly structured molecular variation within an island only 16 km long is discussed.

Crassocephalum rubens, a herb with potential anticancer properties, encounters challenges in production efficiency due to small seed size and elevated temperatures in cultivation areas. Our study investigates the effects of seed pelleting and plant growth-promoting bacteria (PGPB) on germination and seedling growth across temperature variations in Taiwan. Pelleted seeds demonstrate superior germination percentages linked to enhanced seed quality. Elevated temperature, particularly at 30/25 °C, enhanced germination performance, with the highest final germination percentage observed in pelleted seeds treated with water. Unexpectedly, PGPB strains— Klebsiella sp. KsGRB10 and Bacillus sp. BsGFB04—exhibited limited impact on germination rates, showing a marginal increase in seedling growth under 25/20 °C and 30/25 °C, respectively. Air temperature fluctuations influenced seedling vigor, leaf color, and physiological parameters. Remarkably, inoculation with BsGFB04 and KsGRB10 enhanced C. rubens’ tolerance to high-temperature stress conditions. Diurnal measurements in week 4, under 25/20 °C, reveal that PGPB inoculation decreased stomatal conductance and transpiration rate while maintaining the quantum yield of PSII, indicating potentially improved water-use efficiency. This study provides crucial insights into the interplay among PGPB, environmental stress, and the physiology of a wild species, paving the way for further research in the domestication of C. rubens for medicinal herb mass production.

A physiological and metabolic database for various species of Amazonian plants is crucial to the species selection and sustainable utilization of their diversity. We hypothesized that understanding the mobilization of Carapa seed reserves and water uptake during germination could provide insights into the physiological behavior and propagation to differentiate species of the same genus. Given this, the mobilization mechanisms of primary reserves, water uptake, and enzymatic activities in seeds of two species of Carapa (C. guianensis and C. vasquezii) were investigated. The lipid content was high in both species, with a value of 63.7±4.7% for C. guianensis and 55±1.5% for C. vasquezii. C. guianensis showed higher values for the other evaluated reserves. The protein profile highlights a band between 15 and 25 kDa in C. guianensis. As for the enzymatic activities investigated (lipase, amylase, protease, acid phosphatase), C. guianensis showed greater activity for most of them, except for acid phosphatase. Overall, the species showed different metabolic strategies and dynamics regarding the water uptake and use of reserves. Our findings indicate that distinct metabolic pathways are employed during the germination and initial seedling growth stages of two Carapa species. This trait can potentially guide the use and preservation of these species.

Habitat loss and degradation is a leading cause of the current biodiversity crisis. In the lake Saint-Pierre floodplain, agricultural intensification has led to the loss of substantial spawning and rearing areas for the yellow perch ( Perca flavescens Mitchill). Restoring perennial vegetation cover is key to ensure the persistence of the population, but the floodplain conditions limit our ability to do so. In this study, we tested the impact of companion plants ( Avena sativa L., Lolium multiflorum L.) and sowing rate on the establishment success of reed canarygrass ( Phalaris arundinacea L.; RCG) in year 2. RCG tolerates a wide range of environmental conditions and can provide the plant cover essential to the reproduction of yellow perch. We hypothesized that companion plants would reduce weed pressure and in turn improve RCG establishment, and that increasing the sowing rate would improve the establishment success. Contrary to our expectations, using companion plants generally reduced the cover and biomass of RCG. It also led to increased weed prevalence in most treatments. In addition, sowing at high rates did not impact RCG cover and biomass. Sowing RCG alone appears to be the most effective option to establish perennial vegetation supporting the recovery of the yellow perch population.

Ongoing climate change is likely to put increased selection pressures on the phenology of plants, yet for many species their abilities to respond to environmental cues are unknown. The present research focuses on using herbarium specimens to examine how 14 native plant species in Alberta have adjusted or adapted to changes in temperature and precipitation over the past century. We specifically investigate the impact of flowering-time responses and determine (1) whether herbaria collections contain sufficient evidence of these phenological responses to climate in plant species in Alberta, and (2) whether the responses are dependent on the typical moisture regime of their habitat. We compared plants from mesic and xeric habitats in terms of their phenological responses to air temperature and precipitation. In this study, the taxonomic relationships between the species were considered by selecting 14 species representing seven different angiosperm orders (one pair of species for each order). By collating data on the peak flowering date over the past century using preserved specimens, we found that on average, species from xeric habitats are more responsive to temperature, but not precipitation. This tendency might be explained by the thermal properties of mesic habitats, a finding that may lead to ways to predict the degree to which environmental cues will govern flowering.