Root hemiparasites are autotrophic plants that extract water and nutrients from neighboring plants via root connections called haustoria. Hemiparasites are postulated to be particularly sensitive to shade early in life when they must invest in infrastructure aboveground for photosynthesis and belowground for acquiring hosts. To fix sufficient carbon, shaded hemiparasites are predicted to invest less into roots, reducing the opportunity to attach to hosts and increasing mortality. Surviving hemiparasites are predicted to grow more slowly under shade and consequently uptake less from host roots. In turn, these hosts experiencing smaller belowground losses to shaded hemiparasites are predicted to allocate relatively more to shoot growth compared to hosts supporting hemiparasites experiencing more sunlight. We tested these predictions with the perennial root hemiparasite Pedicularis canadensis L. using clusters of seedling and young plants transplanted from a restored prairie to pots containing hosts. Three shade treatments were applied: 50% shade cloth was applied to entire clusters of hemiparasites within pots early in development, 4 wk later, or never. No seedlings survived the experiment. Shade significantly increased mortality of young plants from the previous year, although no pairwise comparisons were significant. Regardless of timing, shade reduced mean biomass of surviving P. canadensis and reduced relative investment into roots. Shading the hemiparasites increased host shoot mass as expected if shade reduced hemiparasite growth and demand on host roots. Our results are consistent with predictions of the balanced-growth hypothesis when light limits hemiparasite growth and parasites limit host growth.

Human generated emissions to the atmosphere have historically increased inorganic nitrogen (N) deposition throughout the Adirondack Mountains of New York. Nitrogen is generally a limiting nutrient for the purple pitcher plant (Sarracenia purpurea L.). Our objective was to determine the dependence of S. purpurea on atmospherically deposited and insect-derived N sources across an increasing nitrogen deposition gradient. Sampling was conducted at 10 sites, with 104 S. purpurea plants sampled. The effects of increasing nitrogen deposition on morphological characteristics and organic N content of S. purpurea and a noncarnivorous reference plant, Chamaedaphne calyculata L. Moench, Leatherleaf, were examined. Sarracenia purpurea flower and C. calyculata leaf tissues were analyzed for stable nitrogen isotope (δ¹⁵N), and foliar N content. Increased nitrogen deposition up to 4.1 kgN*ha⁻¹*yr⁻¹ was correlated with increased plant size and δ¹⁵N values of S. purpurea. However, deposition exceeding these levels decreased overall plant size and δ¹⁵N values. Nitrogen derived from assimilation of insects ranged from 55% to 90% of foliar N at higher N deposition levels. Plants that acquired the greatest amount of N from insect consumption were also the largest plants. These results reflect the importance of monitoring ecologically sensitive species, like S. purpurea, in light of anthropogenic sources of pollution.

Limber pine Pinus flexilis James populations in the southern Rocky Mountains are threatened by the combined impacts of mountain pine beetles and white pine blister rust. To develop restoration planting methods, six P. flexilis seedling planting trial sites were installed along a geographic gradient from southern Wyoming to southern Colorado. Experimental treatments included: high or low overstory canopy density from existing trees, presence/absence of a nurse object, and presence/absence of hydrogel. Of the P. flexilis seedlings planted, 72% were alive after four growing seasons. There were interactions between nurse object, seedling height at planting, and percent canopy cover that affected the number of healthy seedlings. Denser canopy cover was positively correlated with healthier planted seedlings and hydrogels had no effect. Nurse objects promoted healthier seedlings, particularly when canopy cover was low (0–50% cover), and the specific orientation to the nurse object affected seedling health under all levels of canopy cover. In conclusion, for best growth and survival in the first four years after planting, P. flexilis seedlings should be planted under an overstory canopy and on the north or west side of a nurse object, particularly if the canopy cover is low or absent.

This work reviews the distribution and the conservation status of the 12 species of Plantago (Plantaginaceae) native to Brazil and presents potential distribution models for 8 of these species. The modeling procedure was carried out with a new online system dedicated to increase the biogeographic knowledge about plants and fungi in Brazil using different modeling strategies, depending on the number of points available. The models reflected reasonably well the known distribution of each species and can be used for conservation purposes, with the exception of one model for P. brasiliensis. The same points selected for model creation were also used to estimate the extent of occurrence and area of occupancy of these species in Brazil. According to the IUCN (International Union for Conservation of Nature) criteria, six species qualified as being of least concern, one as near threatened, three as endangered, and two as critically endangered. Also, six species of Plantago are exclusive to Brazil (P. catharinea, P. corvensis, P. guilleminiana, P. rahniana, P. trinitatis, and P. turficola), and four threatened species (P. commersoniana, P. corvensis, P. rahniana, and P. trinitatis) are absent or inadequately classified in the “Red List of the Flora of Brazil.” Three nonnative species of Plantago occur in Brazil, all originating from Europe: P. coronopus, P. lanceolata, and P. major.

Bryophytes have an important biogeochemical role in many forest ecosystems, where they regulate soil temperature and moisture and influence carbon and nitrogen (N) cycling. Associations between bryophytes and N₂-fixing cyanobacteria have been reported in northern latitude forests and are shown to provide a substantial N input to these ecosystems, but whether the association extends into temperate forests remains largely unknown. We investigated the extent of bryophyte-cyanobacteria associations in common understory bryophytes in a temperate forest in New York using δ¹⁵N analyses and ultraviolet fluorescence microscopy. Of the seven taxa examined, three (Fissidens taxifolius, Marchantia polymorpha, and Thuidium delicatulum) were associated with cyanobacteria, with colonization observed in 15–85% of the leaves examined. The taxa with cyanobacterial associations exhibited δ¹⁵N values that were 3.9‰ higher compared with taxa that did not, and the δ¹⁵N signatures were close to the atmospheric N₂ signature of zero, suggesting these taxa acquired a measurable fraction of their N from associated cyanobacteria. Taxa that associated with cyanobacteria also had 55% higher tissue %N that did those not associated with cyanobacteria. This study revealed the utility of natural abundance stable N isotope analysis in detecting bryophyte-cyanobacteria symbioses, and also suggests that bryophyte-cyanobacteria associations may represent a significant yet previously unaccounted for N source to the temperate forest biome.

The phylogenetics of the North American genera Asimina and Deeringothamnus (Annonaceae) have never been determined with strong support or resolution. In this analysis, Inter-Simple Sequence Repeat (ISSR) DNA fingerprinting techniques were used alone and in combination with morphological and floral scent chemical data to elucidate the phylogeny of the group. DNA was extracted from accessions from both the field and herbarium. Five ISSR primers were used with 13 taxa, including nine of Asimina, two of Deeringothamnus, one Annona, and one Disepalum (17 total accessions). The ISSR band presence/absence data were analyzed using maximum parsimony. Phenotypic characters (including morphology and floral scent chemistry) were included in addition to the molecular data. In the molecular analysis, Deeringothamnus was imbedded within Asimina, with Deeringothamnus pulchellus Small being sister to two accessions of Asimina triloba Dunal (79% bootstrap [bt] support]. In the combined molecular, morphological, and chemical analysis, the four accessions of Deeringothamnus formed a monophyletic clade (85% bt) as did the white-flowered and maroon-flowered species of Asimina, albeit each with less than 50% bt support.

The cerrado rupestre is a physiognomy of the Cerrado biome with a prominent ground layer. It is characterized by rocky outcrops; acidic, nutrient-poor soil; and water shortage due to climatic seasonality. Species of this biome have several mechanisms to survive these adverse conditions. This study aimed to investigate morpho-anatomical characteristics and soluble carbohydrates in underground systems of Apopyros warmingii and Ichthyothere terminalis (Asteraceae), and to evaluate the potentially adaptive roles of these structures under the environmental stressors of the cerrado rupestre. Samples of underground organs were fixed, dehydrated in graded ethylic ethanol, embedded in historesin, and sectioned. Qualitative and quantitative analyses of soluble carbohydrates were performed in distinct portions of the underground systems. Thickened underground systems of both species are composed of stem and root portions with buds in the proximal region. Vascular and cortical parenchymas are abundant and accumulate inulin, which can be visualized as spherocrystals. Secretory structures have lipophilic secretion. High fructan amounts in the parenchyma indicate their use to support resprouting. These carbohydrates may be mobilized to meet the increased demands of phenology and abiotic factors. Secretory structures and sclereids in both species and raphides in A. warmingii may assist the protection of the underground system against herbivores.

Adenostemma brasilianum is an herbaceous asteracean pollinated by male Ithomiinae butterflies. These insects feed on the nectar, which contains pyrrolizidine alkaloids, and depend on these compounds for their defense and reproduction. The life history of this species was described from seedlings to the death of adult plants. In addition, we analyzed its reproductive phenology and identified herbivores. The study was conducted in southeastern Brazil, in a semideciduous seasonal forest fragment. Fifty plants with up to two pairs of well-defined leaves were monitored, on which we observed buds, flowers, dispersed diaspores, and herbivores. We labeled 140 capitula in the bud stage and monitored them from anthesis of the first flowers to diaspore dispersal. Adenostemma brasilianum is biennial and monocarpic, and establishes a seedling bank within about 9 months (from February to October, in the first year of life). Plant mortality resulting from physical damage was high (46%) at the beginning of the rainy season (from November to December of the first year). At that time, the remaining plants entered the reproductive phase, which lasted until June (the dry season of the second year). In the capitula, the flowers open in a centripetal sequence for four consecutive days. In the first 2 days, 74% of the flowers were in anthesis. On the 20th day of the capitulum, the diaspores were completely exposed. Dispersal began in January (second year). Due to the pappus with viscid glands, diaspore dispersal is epizoochorous, which is an unusual feature among Asteraceae. Herbivory occurred mainly at the end of the reproductive period (July) until plant death (December), in the second year of life. Herbivores were the beetles Agathomerus signatus, Elytrosphoera xarthopyga, and Homophoeta octoguttata. In conclusion, in the short life history of A. brasilianum, abiotic (associated with the maintenance of the seedling bank, plant growth, and mortality) and biotic factors (associated with pollination, dispersion, and herbivory) act in synergy to complete the plant cycle.