Marie Selby Botanical Gardens

The authors describe and illustrate Stigmatodon vinosus, a hyperepilithic new species living on bare, nearly vertical rock walls of a granitic inselberg from Espírito Santo state, southeastern Brazil, of the Tubo-laciniate stigma type, which is characterized by the prevailingly purple-wine floral bracts and sepals at anthesis. Its well-developed floral bracts, which distinctly exceed the sepals, allows the recognition of the morphological affinity of this new species with S. magnibracteatus, another dweller from Espírito Santo state belonging to the so called Stigmatodon s.str. Other morphological affinities as well as the conservation status of this new species are also discussed.

Columnea congestiflora J. L. Clark, Solano-C & Parra-Lizc. (Gesneriaceae), a new species endemic to Buenaventura and discovered in the lowland forests of western Colombia, is described and illustrated. A preliminary conservation assessment based on IUCN Red List criteria supports the classification of the risk of extinction for the species as Endangered (EN).

Field expeditions to the Cordillera Occidental of the Colombian Andes have resulted in the discovery of a new species of Trichodrymonia (Gesneriaceae). Trichodrymonia glutinosa J.L.Clark & Clavijo is described from the western Andean slopes of the Cordillera Occidental, along the old highway between Cali and Buenaventura. The new species is a lithophytic stout herb with elongate pendent leaves and with vegetative and reproductive structures covered with a glutinous indumentum. Based on IUCN guidelines, a preliminary conservation assessment of ‘Vulnerable' (VU) is recommended for T. glutinosa.

Invasive pests and pathogens are a major driver of biodiversity loss. Some rare species may persist through rapid evolution to tolerate or escape new threats, but representing the underlying ecological and evolutionary processes at the appropriate scale is analytically and computationally challenging. Tillandsia utriculata has been classified as endangered in Florida where its population has decreased significantly due to predation by the invasive Mexican weevil Metamasius callizona. Adult female weevils deposit their eggs in leaves of epiphytic bromeliads, preferentially ovipositing in the largest rosettes. Once the eggs hatch, the larvae consume the core of the rosette, often leading to pre-reproductive death. During the past three decades of predation, the T. utriculata population has shifted to initiating the production of inflorescences (to commence its single attempt at sexual reproduction) at smaller rosette sizes. Importantly, the rosette size at induction is correlated with the number of seeds produced. We have constructed an agent-based model to simulate the dynamics of a Florida T. utriculata population over many generations where the minimum rosettes size required to initiate inflorescence production (minimum size of induction or MSI), is an inherited trait. We use the model to explore how predation may have shifted the population’s genetic composition and the impact this has on population viability. Our results show that larger germination rates are required for population viability when weevils are present. Parameter uncertainty analysis revealed that in the presence of weevil predation, only a population with a very high germination rate and a short period of predation would sustain its population for 100 years with sizes similar to simulations without weevil predation. Furthermore, uncertainty analysis showed that the mean MSI of the population decreased over a 100-year period without weevil predation, and this trend was exacerbated by the presence of weevil predation.

A new species, Ormosianeillii (Fabaceae), is described and illustrated from the tepui-like formations of the Cordillera del Cóndor Region in south-eastern Ecuador. Morphological similarities with other species of Ormosia are examined and discussed. Based on IUCN guidelines, a preliminary conservation status of Endangered (EN) is recommended.

Abstract The Neotropical realm hosts some of the Earth’s most species-rich biodiversity hotspots, with vascular epiphytes significantly contributing to this diversity. However, many regions of the Neotropics where epiphytic species of restricted distribution are reported coincide with threatened ecosystems, such as the tropical montane cloud forest. Moreover, epiphytes may be especially vulnerable to land use and climate change impacts due to their dependence on host trees. We assessed the conservation status of vascular epiphytes in the Neotropics for the families that represent over 80% of the global epiphyte diversity (Araceae, Bromeliaceae, Orchidaceae, Piperaceae, and Polypodiaceae) and identified geographical centers of accumulation of threatened epiphyte species. We gathered information from free-access web repositories, specific epiphytic plant databases, and scientific and grey literature. We assessed the extinction risk of 11,446 epiphyte species following IUCN Red List guidelines, using Criterion B (geographic range size). We found nearly 60% (6,721 species) to be threatened, with 1,766 critically endangered (CR), 3,537 endangered (EN), and 1,418 vulnerable (VU). The threatened species are mainly found in the centers of endemism of vascular epiphytes in Central America, the northern Andes, and the Atlantic Forest. Our study emphasises that the centers of threatened species largely coincide with diversity hotspots, highlighting epiphytes as an especially vulnerable group that requires urgent conservation actions.

The transmission of seed-borne pathogens by the germinating seed is responsible for major crop diseases. The immune responses of the seed facing biotic invaders are poorly documented so far. The Arabidopsis thaliana/Alternaria brassicicola patho-system was used to describe at the transcription level the responses of germinating seeds and young seedling stages to infection by the necrotrophic fungus. RNA-seq analyses of healthy versus inoculated seeds at 3 days after sowing (DAS), stage of radicle emergence, and at 6 and 10 DAS, two stages of seedling establishment, identified thousands of differentially expressed genes by Alternaria infection. Response to hypoxia, ethylene and indole pathways were found to be induced by Alternaria in the germinating seeds. However, surprisingly, the defense responses, namely the salicylic acid (SA) pathway, the response to reactive oxygen species (ROS), the endoplasmic reticulum-associated protein degradation (ERAD) and programmed cell death, were found to be strongly induced only during the latter post-germination stages. We propose that this non-canonical immune response in early germinating seeds compared to early seedling establishment was potentially due to the seed-to-seedling transition phase. Phenotypic analyses of about 14 mutants altered in the main defense pathways illustrated these specific defense responses. The unexpected germination deficiency and insensitivity to Alternaria in the glucosinolate deficient mutants allow hypothesis of a trade-off between seed germination, necrosis induction and Alternaria transmission to the seedling. The imbalance of the SA and jasmonic acid (JA) pathways to the detriment of the JA also illustrated a non-canonical immune response at the first stages of the seedling.

Abstract A new species of Cryptanthus, known exclusively from Chapada Diamantina, in the municipalities of Miguel Calmon and Jacobina, state of Bahia, Northeast Brazil, is described and illustrated. Cryptanthus euglossinii is characterized by having leaves that are reddish in the marginal region, white-scaly near the base and glabrous adaxially towards the apex, with the abaxial surface covered by trichomes that obscure the color of the leaf. Comparisons are made with two similar species, C. reisii and C. bibarrensis, that are considered closely related. Euglossinii bees were observed visiting the flowers of C. euglossinii and collecting floral essences on petals, a relationship that is the basis of the epithet of the new species. Cryptanthus euglossinii is considered Endangered (EN) based on an extent of occurrence of 860 km2, an area of occupancy of 1,000 km2, and criteria established by the IUCN.

Abstract— Habenaria longissima, a new species from the H. nuda species complex, is described and illustrated. It is remarkable for the exceptionally long lateral segments of the petals and labellum, which are the longest among Neotropical Habenaria, both in absolute and in proportional terms. Despite the morphological similarity, Bayesian and parsimony phylogenetic analyses based on nuclear (ITS) and plastid DNA markers (matK), revealed that H. longissima is distantly related to other species of the complex, and constitutes an independent lineage. Its distribution is unusual in that it is the only species of Orchidaceae restricted to the Quadrilátero Ferrífero in the State of Minas Gerais and to Chapada Diamantina, in the central part of the Espinhaço range in the State of Bahia, with the populations 1000 km from each other. Habenaria longissima is a rare species, known only from three localities and four populations and informally proposed as Endangered due to the small area of occupancy and small number of known populations.