A series of unfortunate events: the forgotten botanist and the misattribution of a type collection

In 1777, Spain sent The Royal Expedition to Peru and Chile, commonly referred to as the “Ruiz and Pavón Expedition”, to document the flora of this richly diverse part of its colonies. The Expedition was active in the New World for 38 years and was led by Hipólito Ruiz and José Pavón, who collected in Peru and Chile for the first 11 years before returning to Spain to work on publication of the Flora Peruviana, et Chilensis. Work on the ground for the reminder of the project in Peru and later Ecuador, was continued by Juan Tafalla and Juan Manzanilla. With few exceptions, all collections from the Expedition including types, have conventionally been attributed to Ruiz and Pavón despite the fact that Tafalla and Manzanilla were responsible for a large part of the collections. The purpose of this note is to bring to light the important but often overlooked figure of Juan Tafalla, to highlight his accomplishments as a collector and to increase precision in botanical nomenclature by giving him due credit by correctly attributing collections

Characterizing the Cauline Domatia of Two Newly Discovered Ecuadorian Ant Plants in Piper: An Example of Convergent Evolution

The stems of some myrmecophytes in Piper are used as domatia by resident ant colonies. Hollow, ant-occupied stems were previously known only in four species of southern Central American Piper, all members of Section Macrostachys. Here we present two additional, unrelated, hollow-stemmed myrmecophytes from Ecuador: P. immutatum and P. pterocladum (members of sections Radula and Peltobryon, respectively). Although similar superficially, stem cavities of the Ecuadorian Piper species differ morphologically and developmentally from those of Central American taxa. The stem cavities of P. immutatum, and possibly P. pterocladum, are formed during stem development, and begin forming only a few millimeters behind the apical meristem. This mode of cavity formation differs markedly from myrmecophytes in section Macrostachys, where the stems remain solid unless excavated by the specialized ant partner Pheidole bicornis. The stems of P. immutatum and P. pterocladum do not produce wound-response tissue around the cavity, unlike the stems in section Macrostachys. The entrance holes in stems of P. immutatum are formed through apoptotic processes and are located at each node below the petiole, whereas those in section Macrostachys are excavated by the ants in the leaf axil. This study documents convergent evolution of ant-plant associations in Piper, and emphasizes the need for careful comparison of apparently homologous, ant-associated structures in specialized myrmecophytes

Allozyme variation and the taxonomy of Wolffiella

Abstract Allozyme electrophoresis was carried out to estimate genetic diversity within and assess divergence between the 10 recognized species in three sections of the aquatic angiosperm genus Wolffiella. Eleven presumptive loci were used in the calculations. Crawford et al. /Aquatic Botany 58 (1997) [43][44][45][46][47][48][49][50][51][52][53][54] Allozyme data support the recognition of sect. Stipitatae as now constituted and provide evidence for the circumscription of sect. Wolffiella as presently recognized. However, W. denticulata is rather isolated within this section. © 1997 Elsevier Science B.V

Multiple recent horizontal transfers of the cox1 intron in Solanaceae and extended co-conversion of flanking exons

Background: The most frequent case of horizontal transfer in plants involves a group I intron in the mitochondrial gene cox1, which has been acquired via some 80 separate plant-to-plant transfer events among 833 diverse angiosperms examined. This homing intron encodes an endonuclease thought to promote the intron´s promiscuous behavior. A promising experimental approach to study endonuclease activity and intron transmission involves somatic cell hybridization, which in plants leads to mitochondrial fusion and genome recombination. However, the cox1 intron has not yet been found in the ideal group for plant somatic genetics - the Solanaceae. We therefore undertook an extensive survey of this family to find members with the intron and to learn more about the evolutionary history of this exceptionally mobile genetic element. Results: Although 409 of the 426 species of Solanaceae examined lack the cox1 intron, it is uniformly present in three phylogenetically disjunct clades. Despite strong overall incongruence of cox1 intron phylogeny with angiosperm phylogeny, two of these clades possess nearly identical intron sequences and are monophyletic in intron phylogeny. These two clades, and possibly the third also, contain a co-conversion tract (CCT) downstream of the intron that is extended relative to all previously recognized CCTs in angiosperm cox1. Re-examination of all published cox1 genes uncovered additional cases of extended co-conversion and identified a rare case of putative intron loss, accompanied by full retention of the CCT. Conclusions: We infer that the cox1 intron was separately and recently acquired by at least three different lineages of Solanaceae. The striking identity of the intron and CCT from two of these lineages suggests that one of these three intron captures may have occurred by a within-family transfer event. This is consistent with previous evidence that horizontal transfer in plants is biased towards phylogenetically local events. The discovery of extended co-conversion suggests that other cox1 conversions may be longer than realized but obscured by the exceptional conservation of plant mitochondrial sequences. Our findings provide further support for the rampant-transfer model of cox1 intron evolution and recommend the Solanaceae as a model system for the experimental analysis of cox1 intron transfer in plants.Fil: Sánchez Puerta, María Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Abbona, Cinthia Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Zhuo, Shi. Indiana University; Estados UnidosFil: Tepe, Eric J.. University of Cincinnati; Estados Unidos. University of Utah; Estados UnidosFil: Bohs, Lynn. University of Utah; Estados UnidosFil: Olmstead, Richard G.. University of Washington; Estados UnidosFil: Palmer, Jeffrey D.. Indiana University; Estados Unido

Ariel - Volume 8 Number 4

Executive Editor James W. Lockard Jr. Issues Editor Neeraj K. Kanwal Business Manager Neeraj K. Kanwal University News Martin Trichtinger World News Doug Hiller Opinions Elizabeth A. McGuire Features Patrick P. Sokas Sports Desk Shahab S. Minassian Managing Editor Edward H. Jasper Managing Associate Brenda Peterson Photography Editor Robert D. Lehman, Jr. Graphics Christine M. Kuhnl

Morphological Trait Evolution in Solanum (Solanaceae): Evolutionary Lability of Key Taxonomic Characters

Solanum is one of the world\u27s largest and economically most important plant genera, including 1245 currently accepted species and several major and minor crops (e.g., tomato, potato, brinjal eggplant, scarlet eggplant, Gboma eggplant, lulo, and pepino). Here we provide an overview of the evolution of 25 key morphological traits for the major and minor clades of this giant genus based on stochastic mapping using a well-sampled recently published phylogeny of Solanum. The most evolutionarily labile traits (showing \u3e100 transitions across the genus) relate to plant structure (growth form and sympodial unit structure), herbivore defence (glandular trichomes), pollination (corolla shape and colour), and dispersal (fruit colour). Ten further traits show evolutionary lability with 50–100 transitions across the genus (e.g., specialised underground organs, trichome structure, leaf type, inflorescence position and branching, stamen heteromorphism). Our results reveal a number of highly convergent traits in Solanum, including tubers, rhizomes, simple leaves, yellow corollas, heteromorphic anthers, dioecy, and dry fruits, and some unexpected pathways of trait evolution that could be explored in future studies. We show that informally named clades of Solanum can be morphologically defined by trait combinations providing a tool for identification and enabling predictive phylogenetic placement of unsampled species

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file