Loma Formation Research Articles

Two new records for the agrostological flora of Peru

The presence of Piptochaetium bicolor (Vahl) É.Desv. and Trichachne californica var. villosissima (Henrard) Wipff & R.B. Shaw are recorded for the first time based upon collections made in the lomas formations of the Department of Arequipa. Piptochaetium bicolor has a recorded distribution as native to Argentina, Brazil, Chile, and Uruguay. Trichachne californica has a recorded distribution as native to southwestern US, Mexico, Caribbean, and through South America and its var. villosissima has been recorded previously from Argentina, Bolivia, Caribben, Colombia, Paraguay and Venezuela. Descriptions, photographs and illustrations are presented for each taxon.

Feeding behaviour and food preferences of native and introduced snail species from the Lomas formations, threatened seasonal fog oases

The Lomas formations are ephemeral seasonal oases found along the Pacific arid coast of South America. Whereas fast-growing plants are characteristic in the Lomas, other organisms such as land snails are also conspicuous. In the Lomas, several snails can occur sympatrically and therefore they might have adapted their food requirements to the limited available items while avoiding competing for food (resource partitioning). Since the dietary items and food preferences of Lomas’ snails are almost completely unknown, our study aimed to document these in three snails occurring sympatrically, two native (Succinea peruviana and Bostryx conspersus) and one introduced (Cornu aspersum) species in Lomas de Lucumo, a threatened Lomas from Central Peru. We recorded the snails’ activity, host, and food items. We also carried out dual-choice bioassays to evaluate the feeding preferences of B. conspersus and C. aspersum when offered leaf disks of the two dominant plant Lomas species, Senecio abadianus and Sicyos baderoa. Whereas we were unable to record any food item used by C. aspersum, we recorded the two native Lomas species (B. conspersus and S. peruviana) having contrasting patterns of feeding as they were on different hosts (plants vs soil) and food items (vascular plants vs. lichens/organic material/mosses/algae). Although the feeding preferences were similar between B. conspersus and C. aspersum (i.e., both species preferred the leaves of Si. baderoa over Se. abadianus), C. aspersum, after feeding stimulation, consumed significantly less leaf area of Se. abadianus than B. conspersus. Sicyos individuals are fast-growing plants and might be less herbivore-resistant, while Senecio species are characterized to produce defensive alkaloids which make plants less palatable. Our results indicate that Lomas’ snail species have evolved distinct trophic niches by partitioning the limited food resources and native herbivorous species are better adapted to feed on Lomas’ native plants given their common evolutionary history.

Flora diversity survey and establishment of a plant DNA barcode database of Lomas ecosystems in Peru

Lomas formations or “fog oases” are islands of vegetation in the desert belt of the west coast of South America, with a unique vegetation composition among the world’s deserts. However, plant diversity and conservation studies have long been neglected, and there exists a severe gap in plant DNA sequence information. To address the lack of DNA information, we conducted field collections and laboratory DNA sequencing to establish a DNA barcode reference library of Lomas plants from Peru. This database provides 1,207 plant specimens and 3,129 DNA barcodes data corresponding with collections from 16 Lomas locations in Peru, during 2017 and 2018. This database will facilitate both rapid species identification and basic studies on plant diversity, thereby enhancing our understanding of Lomas flora’s composition and temporal variation, and providing valuable resources for conserving plant diversity and maintaining the stability of the fragile Lomas ecosystems.

New nephropid lobster (Decapoda: Astacidea) from the late Campanian of California; extending the range of Pacific coastal fossil lobster occurrences

Two well preserved specimens of nephropid lobster from the Late Cretaceous (late Campanian) Point Loma Formation in San Diego County, California, form the basis of description of a new species of Hoploparia. The occurrence represents the southernmost fossil record of macrurans along the Pacific coast of North America and it is only the third fossil lobster from California.

Quantifying the lateral heterogeneity of distal submarine lobe deposits, Point Loma Formation, California: Implications for subsurface lateral facies prediction

AbstractSubmarine fan deposits are volumetrically the largest sediment accumulations on Earth and host significant hydrocarbon reserves. Extensive research has documented the bed‐scale architecture of high sand‐to‐mud ratio, proximal and axial environments, which can have bed thicknesses of several metres; however, less well‐understood are thin‐bedded turbidites, which are typically lower N:G and deposited in more distal environments. Conceptual models assume that lobe‐fringe‐to‐basin plain environments consist of tabular, sheet‐like beds that extend out continuously and predictably over long distances—up to several kilometres. Extensive lateral continuity, however, is not necessarily reflected in ancient outcrop analogues. This study seeks to apply a quantitative approach to the characterisation of thin‐bedded turbidites to assess the impact of multi‐scale heterogeneity on reservoir predictability. The sea‐cliff outcrop exposures of the Upper Cretaceous Point Loma Formation in San Diego, California, exhibit a wide range of bed thicknesses and stratigraphic architecture, which have been used to interpret an off‐axis‐to‐fringe depositional environment. The study area spans 700 m of laterally continuous outcrop, across which 10 correlated stratigraphic sections are used to quantify changes in metrics such as bed thickness, N:G, lithofacies proportions, etc. Results of this study demonstrate that thin sand beds experience both lateral facies changes and rapid thickness changes more frequently than conceptual models would predict. A single measure of lateral heterogeneity does not reflect the true architecture of sandstone beds, and significant information is lost when beds are correlated over ten to hundreds of metres. Sands are commonly deposited in irregular, ‘finger‐like’, planform geometries, which compounds at the lobe element scale and influences lateral lithofacies predictability. This study of the Point Loma Formation offers high‐resolution bed‐to‐element scale data, which may be used as inputs for reservoir models and horizontal facies predictions in both conventional and unconventional hydrocarbon reservoirs.

A Fine-Scale Hotspot at the Edge: Epigean Arthropods from the Atacama Coast (Paposo-Taltal, Antofagasta Region, Chile).

Simple SummaryThe identification and surveying of fine-scale or micro-hotspots of biodiversity is a crucial strategy for better driving conservation efforts at global hotspots. This seems to be especially relevant at the edges of environments suitable for life, i.e., in desert margins with high levels of endemism, such as the Atacama coast. We surveyed a 100 km section of the Atacama coast including the emblematic Paposo and Taltal sites. We studied the taxonomic composition, richness, and abundance of terrestrial arthropods and were able to identify 173 arthropod species grouped into 118 genera and 57 families. The most abundant orders were Hymenoptera, Coleoptera, and Collembola, which accounted for 90.0% of the total captured. Most abundant families were Melyridae (Coleoptera), Poduridae (Collembola), Tenebrionidae (Coleoptera), and an indeterminate family of Psocoptera. Among remarkable Coleoptera, we were able to register Ectinogonia barrigai (Buprestidae) and Luispenaia paposo (Scarabaeidae). We also documented the presence of the tenebrionid Gyriosomus angustus, and several species of the genera Nycterinus (Paranycterinus) and Scotobius. We also could find the four species of scorpions that have been described for the Paposo area recently, and an undescribed species. The relevance of the area for future prospections and as a conservation site and a fine-scale hotspot of biodiversity has been confirmed based on the epigean arthropods.The Atacama Desert at its margins harbors a unique biodiversity that is still very poorly known, especially in coastal fog oases spanning from Perú towards the Atacama coast. An outstanding species-rich fog oasis is the latitudinal fringe Paposo-Taltal, that is considered an iconic site of the Lomas formation. This contribution is the first to reveal the knowledge on arthropods of this emblematic coastal section. We used pitfall traps to study the taxonomic composition, richness, and abundance of terrestrial arthropods in 17 sample sites along a 100 km section of the coast between 24.5 and 25.5 southern latitude, in a variety of characteristic habitats. From a total of 9154 individuals, we were able to identify 173 arthropod species grouped into 118 genera and 57 families. The most diverse group were insects, with 146 species grouped in 97 genera and 43 families, while arachnids were represented by 27 species grouped into 21 genera and 14 families. Current conservation challenges on a global scale are driving the creation and evaluation of potential conservation sites in regions with few protected areas, such as the margins of the Atacama Desert. Better taxonomic, distributional, and population knowledge is urgently needed to perform concrete conservation actions in a biodiversity hotspot at a desert edge.

Submarine lobe deposits of the Point Loma Formation, California: Quantifying event‐bed architecture and lateral heterogeneity

AbstractOver the last several years, numerous outcrop localities have been revisited to add quantitative detail to submarine lobe facies models that previously focussed on facies relationships in a qualitative sense. This study utilises well‐exposed submarine lobe deposits of the Point Loma Formation in Cabrillo National Monument (San Diego, CA) to provide quantitative and statistical insights into the lateral variability of event‐bed (i.e. turbidite) architecture within and between lobe elements. Within a lobe element (defined as a surface‐bounded, genetically related package), event beds compensationally stack, thinning over subtle sea floor topography created by the previous event bed. Between lobe elements, larger‐scale compensation is observed, with clearly defined stratal surfaces and facies architecture distinguishing the four lobe elements. A lateral facies transition is observed for one lobe element, where sandstone beds pinch out and the element thickness halves over a distance of 100 m. However, architectural parameters of event beds (e.g. bed thickness, thinning rate, fining rate) are not appreciably different between these elements, suggesting that the observed stratal architecture does not readily translate into vertical bed thickness (i.e. stacking) patterns that could be easily recognised in common subsurface data types like borehole‐derived core. While the data derived from this outcrop study are valuable for improving the construction of realistic geological and reservoir models, caution is necessary when interpreting lobe element boundaries from borehole data. The lobe deposits measured in this study have event‐bed thicknesses and thinning rates most similar to semi‐confined proximal lobes, suggesting a more proximal position and more confined than previously interpreted. Based on the relationships between sandstone and mudstone thicknesses and thinning rates, bed and lobe‐element compensation and minimal evidence of erosion, the Point Loma Formation at Cabrillo National Monument is reinterpreted as a medial lobe environment with some degree of lateral and/or frontal confinement.

Diet and behavior of the burrowing owl (Athene cunicularia) in Atiquipa, an ecosystem of Lomas in the south of Peru

Abstract. Luque-Fernández CR. 2019. Diet and behavior of the burrowing owl (Athene cunicularia) in Atiquipa, an ecosystem of Lomas in the south of Peru. Biodiversitas 20: 137-143. The study of trophic and behavioral habits is a fundamental aspect in the knowledge of the natural history of species, especially for those that present a wide range of distribution and that have to adapt to the habitats and available resources that can find to survive. The diet and behavior of Athene cunicularia were studied in a peculiar ecosystem such as the lomas formation, on the arid coast of southern Peru. The analysis of regurgitated pellets from a family group of Athene cunicularia was used and complemented with the monitoring of behavior through the use of trap cameras and direct observations. The results show that the diet during the months of study was based on a high proportion of invertebrate beetles (Tenebrionidae) and scorpions, also finding remains of vertebrates, including rodents, birds and highlighting the presence of a species of marsupial mouse. On the study of behavior, marked and recurrent activities are established during the day for this species, where grooming sessions are frequently reported, as well as interaction with a possible predator of this owl species. These results contribute to the understanding of the trophic relationship and its role in the studied lomas ecosystem, which is added to the importance of this species in the conservation of diversity in desert ecosystems.

Five new scorpion species of genus Brachistosternus (Scorpiones: Bothriuridae) from the deserts of Chile and Peru, with comments about some poorly studied diagnostic characters of the genus.

Five new scorpion species of genus Brachistosternus of Chile and Peru are described. Brachistosternus gayi n. sp. is a high Andean species of north central Chile. Brachistosternus philippii n. sp. occurs near the coast of Antofagasta. Brachistosternus misti n. sp. occurs at intermediates altitudes of southern Peru. Brachistosternus contisuyu n. sp. occurs in Lomas formation in southern Peru. Brachistosternus anandrovestigia n. sp. occurs in coastal areas of southern Peru, and is the second known species of the genus without metasomal glands or androvestigia. Two diagnostic characters are discussed: the Internal Laminar Apophysis of the right hemispermatophore, and the sternum macrosetae.

The Late Cretaceous Chimaeroid Fish,Ischyodus bifurcatusCase (Chondrichthyes: Holocephali), from California, USA, and Its Paleobiogeographical Significance

A nearly complete right mandibular tooth plate of Ischyodus bifurcatus Case (Holocephali: Chimaeroidei) is reported from the Point Loma Formation (upper Campanian) of the Upper Cretaceous Rosario Group in southern California, USA. The individual is estimated to have measured nearly 1 m in total body length. Remains of I. bifurcatus have been reported from marine rocks deposited in epicontinental seas and continental shelf paleoenvironments of temperate latitudes in the Northern Hemisphere. Previous records of the species consist of specimens from Santonian to Maastrichtian strata of the US (Delaware, New Jersey, North Carolina, Georgia, Alabama, Arkansas, Montana, and Wyoming), Sweden, and European Russia. The tooth plate described herein is the first verifiable record of I. bifurcatus from California, and, more significantly, represents the only known definite Mesozoic record of Ischyodus from the entire North Pacific region.

Recognizing Non-Steady-State Weathering Conditions In Ancient Submarine Fan Systems: Correcting For K-Metasomatism Reveals A Late Cretaceous Non-Steady-State Weathering Regime, Point Loma Formation, Southwestern California, U.S.A.

Abstract: During steady-state weathering, the rate of removal of the exposed weathering zone is balanced by the rate of generation of mineralogically identical material through chemical weathering. As steady-state conditions prevail, the mineralogical and chemical composition of sediments derived from the weathering profile should be invariant over time. In A-CN-K space, a steady-state weathering condition is characterized by tightly grouped compositions, with dispersion between sands and muds a consequence of sorting during fluvial transportation. The purpose of this study was to assess whether such a condition was present during the development of the Upper Cretaceous Point Loma Formation. Published paleotectonic reconstructions portray the upper Campanian–lower Maastrichtian(?) Point Loma Formation as being deposited in a forearc basin developed westward of a continental-margin magmatic arc. In such accounts, during the subduction of an oceanic plateau (or aseismic ridge) or during constant-dip subduction, rocks in the magmatic arc were uplifted and the volcanic cover nearly stripped clean, exposing its plutonic roots. Published detrital-zircon data derived from samples of the Point Loma Formation indicate that exposed igneous rocks in the source area were mainly from 135 Ma to 100 Ma plutons located in the western zone of the Peninsular Ranges batholith. New point-count, XRD, and chemical data show that detritus in mudstones and some fine-grained feldspathic sandstones of the Point Loma Formation following deposition and shallow burial were subjected to a K-metasomatic event. After correcting for introduction of K + , and consideration of the effects of hydraulic sorting, resulting mudstone and fine-grained sandstone data plot in A-CN-K space in overlapping fields, whereas samples of coarse-grained sandstone lie between rays extending through the most and least weathered mudstones. Hence, detritus in the Point Loma Formation was derived mainly from regolith during non-steady-state weathering conditions.

Myxomycete diversity in the coastal desert of Peru with emphasis on the lomas formations

Results obtained from the first survey for myxomycetes in the hyperarid areas of Peru are reported. Sampling over three consecutive years was carried out at 96 localities between 0 and 1500 m elevation. A total of 78 species from 23 genera in all 6 myxomycete orders were determined from 723 collections of myxomycetes. One new species, Didymium peruvianum , is described, 2 species new to the Neotropics, 4 new records for South America and 41 additional new species for Peru are reported, increasing the country catalogue by over 50%. Results show that arid areas are rich in myxomycetes, and that each area has a unique species assemblage. Endemic plants had a particular relevance as myxomycete substrates. The predominance of the order Physarales in arid areas is reinforced, and the ecological importance of coastal fogs (garuas) is evident from the results. Comments are included on interesting or rare collections, as are SEM micrographs of several species and statistical evaluation of the results.

Re-evaluating the resource potential of lomas fog oasis environments for Preceramic hunter–gatherers under past ENSO modes on the south coast of Peru

Lomas – ephemeral seasonal oases sustained by ocean fogs – were critical to ancient human ecology on the desert Pacific coast of Peru: one of humanity's few independent hearths of agriculture and “pristine” civilisation. The role of climate change since the Late Pleistocene in determining productivity and extent of past lomas ecosystems has been much debated.Here we reassess the resource potential of the poorly studied lomas of the south coast of Peru during the long Middle Pre-ceramic period (c. 8000–4500 BP): a period critical in the transition to agriculture, the onset of modern El Niño Southern Oscillation (‘ENSO’) conditions, and eustatic sea-level rise and stabilisation and beach progradation.Our method combines vegetation survey and herbarium collection with archaeological survey and excavation to make inferences about both Preceramic hunter–gatherer ecology and the changed palaeoenvironments in which it took place. Our analysis of newly discovered archaeological sites – and their resource context – show how lomas formations defined human ecology until the end of the Middle Preceramic Period, thereby corroborating recent reconstructions of ENSO history based on other data.Together, these suggest that a five millennia period of significantly colder seas on the south coast induced conditions of abundance and seasonal predictability in lomas and maritime ecosystems, that enabled Middle Preceramic hunter–gatherers to reduce mobility by settling in strategic locations at the confluence of multiple eco-zones at the river estuaries. Here the foundations of agriculture lay in a Broad Spectrum Revolution that unfolded, not through population pressure in deteriorating environments, but rather as an outcome of resource abundance.

Seed dormancy of Nolana jaffuelii I.M.Johnst. (Solanaceae) in the coastal Atacama Desert

Nolana (Solanaceae) is a genus composed of 88 species that inhabit arid and semi-arid environments throughout the Atacama Desert of Chile and Peru, and one from Galapagos Islands. Its greatest diversity is found in coastal localities, termed lomas formations, which are small isolated patches of vegetation sustained by the presence of low cloud layers. Alto Patache corresponds to one of these ecosystems, and Nolana jaffuelii I.M. Johnst., a summer annual herb, is the most abundant species in its persistent seed bank. Little is known about the seed germination requirements of this and other species present in Chilean lomas formations, despite the importance of that knowledge for taking appropriate conservation actions. The main objective of this study was to identify the germination requirements and possible dormancy mechanisms of N. jaffuelii’s dispersal units, which are mericarps. Mature mericarps of N. jaffuelii were collected at Alto Patache. Histological analyses of cross and longitudinal sections of the mericarps suggested the presence of physical dormancy imposed by an impermeable pericarp. Different germination treatments were also evaluated: (T1) control, i.e., intact mericarps imbibed in water; (T2) intact mericarps washed under running water; (T3) scarified mericarps (cut at the funicular scar) imbibed in water; (T4) scarified mericarps imbibed in gibberellic acid (500mg l−1 GA3); (T5) scarified mericarps imbibed in water with 2 weeks of stratification at 4°C; and (T6) intact mericarps imbibed in GA3. Only mericarps cut at the funicular scar were able to germinate, and the highest germination percentage was observed when the mericarps were imbibed in GA3 (T4). The results of this investigation reveal the existence of physical and physiological dormancy in N. jaffuelii propagules, an adaptation that would allow this species to spend long periods waiting for favorable conditions for seedling establishment, which is characteristic of the coastal lomas formations of the Atacama Desert.

Predictive Mapping of Species Richness and Plant Species' Distributions of a Peruvian Fog Oasis Along an Altitudinal Gradient

AbstractTropical arid to semi‐arid ecosystems are nearly as diverse as more humid forests and occupy large parts of the tropics. In comparison, however, they are vastly understudied. For instance, fog precipitation alone supports a unique vegetation formation, locally termed lomas, on coastal mountains in the Peruvian desert. To effectively protect these highly endemic and threatened ecosystems, we must increase our understanding of their diversity patterns in relation to environmental factors. Consequently, we recorded all vascular species from 100 random 4 × 4 m plots on the fog‐exposed southern slope of the mountain Mongón. We used topographic and remotely sensed covariates in statistical models to generate spatial predictions of alpha diversity and plant species' distribution probabilities. Altitude was the most important predictor in all models and may represent fog moisture levels. Other significant covariates in the models most likely refer also to water availability but on a finer spatial scale. Additionally, model‐based clustering revealed five altitudinal vegetation zones. This study contributes to a better spatial understanding of the biodiversity and spatial arrangement of vegetation belts of the largely unknown but highly unique lomas formations. Furthermore, mapping species richness and plant species' distributions could support a long‐needed lomas strategic conservation scheme.

Molecular evidence for the polyphyly of Bostryx (Gastropoda: Bulimulidae) and genetic diversity of Bostryx aguilari

Bostryx is largely distributed in Andean Valleys and Lomas formations along the coast of Peru and Chile. One species, Bostryx aguilari, is restricted to Lomas formations located in the Department of Lima (Peru). The use of genetic information has become essential in phylogenetic and population studies with conservation purposes. Considering the rapid degradation of desert ecosystems, which threatens the survival of vulnerable species, the aim of this study was, first, to resolve evolutionary relationships within Bostryx and to determine the position of Bostryx within the Bulimulidae, and second, to survey the genetic diversity of Bostryx aguilari, a species considered rare. Sequences of the mitochondrial 16S rRNA and nuclear rRNA regions were obtained for 12 and 11 species of Bulimulidae, respectively, including seven species of Bostryx. Sequences of the 16S rRNA gene were obtained for 14 individuals (from four different populations) of Bostryx aguilari. Phylogenetic reconstructions were carried out using Neighbor-Joining, Maximum Parsimony, Maximum Likelihood and Bayesian Inference methods. The monophyly of Bostryx was not supported. In our results, B. solutus (type species of Bostryx) grouped only with B. aguilari, B. conspersus, B. modestus, B. scalariformis and B. sordidus, forming a monophyletic group that is strongly supported in all analyses. In case the taxonomy of Bostryx is reviewed in the future, this group should keep the generic name. Bostryx aguilari was found to have both low genetic diversity and small population size. We recommend that conservation efforts should be increased in Lomas ecosystems to ensure the survival of B. aguilari, and a large number of other rare species restricted to Lomas.

ENSO Impacts on Lomas Formation in South Coastal Peru: Implications for the Pliocene?

Lomas formations in southern Peru are related to moisture availability due to frequent incursions of fog in austral winter. Due to warming of coastal waters of southern Peru during El Niño, lomas formations are enhanced via greater moisture availability for fog and drizzle. Our study evaluates the modern climatological record in austral winter to determine if there are differences in moisture availability between El Niño and La Niña for fog formation. Our results show anomalous northwesterly onshore flow, warmer than normal sea-surface temperatures, and an increase in precipitable water in El Niño, favoring lomas formations due to advection fog with higher moisture content. On the other hand, La Niña also favors frequent advection fog, with less moisture content due to strong onshore flow over relatively cool SSTs. Since lomas may represent fragments of a continuous vegetation belt that existed during the Pliocene, a permanent El Niño favoring vigorous vegetation production along the south Peruvian coast due to incursions of fog with high precipitable water may have occurred in this period. However, the possibility of normal El Niño variability superimposed on a warmer climatology producing fog with higher moisture content in both El Niño and La Niña conditions cannot be discounted.

Aa from lomas formations. A new Orchidaceae record from the desert coast of Peru

Las especies del género Aa han sido descritas como orquídeas restringidas generalmente a zonas altas de los Andes y montañas de Costa Rica. Se presenta el registro de poblaciones de Aa weddelliana a elevaciones más bajas, en formaciones de lomas en la costa desértica del Perú, siendo ésta la cuarta especie de Orchidaceae registrada para las formaciones de lomas. Asimismo, ilustramos y discutimos algunos aspectos florísticos de Aa weddelliana.

Phylogenetic Analysis of <I>Palaua</I> (Malveae, Malvaceae) based on Plastid and Nuclear Sequences

Palaua, a genus of 15 species endemic to the fog-influenced lomas formations amidst the coastal deserts of Peru and Chile, is characterized by its unique irregularly arranged, superimposed carpels. The only exception to this character is P. sandemanii, which has carpels arranged in a single whorl, the state observed in the potential sister groups. To investigate the monophyly of Palaua and to compare previous infrageneric classifications in a phylogenetic framework, parsimony and Bayesian analyses were performed using plastid (psbA-trnH intergenic spacer) and nuclear (internal transcribed spacers 1 and 2) DNA sequences. There is evidence for three clades within a monophyletic Palaua: one comprising the two small-flowered species, P. inconspicua and P. modesta, as sister to the rest of the genus, a second uniting all species with dissected leaves, and a third containing the rest of the genus (species with entire to shallowly lobed leaves; except P. guentheri). In contrast to our expectations, P. sandemanii could not be confirmed as sister to the rest of the genus, but rather is nested within a monophyletic Palaua. Parsimony-based reconstruction of the evolution of carpel arrangement showed that there was a change in Palaua from superimposed, irregularly arranged carpels to uniseriate carpels in P. sandemanii; however, Templeton and Shimodaira-Hasegawa tests did not reject the alternative hypothesis that the uniseriate carpels are ancestral. Besides carpel arrangement, leaf division (and not growth form) seems to be an appropriate character for infrageneric classification.

Three New Species of Jaltomata (Solanaceae) from Ancash, Peru

Three new Jaltomata species from the department of Ancash, Peru, are described and illustrated. The three species are distinguished from others in the genus by features of the flowers, hairs, and leaves. Fruits of Jaltomata cajacayensis S. Leiva & Mione are gathered for consumption. Jaltomata lomana Mione & S. Leiva is known only from a single fog-dependent plant community, a lomas formation. Jaltomata yungayensis Mione & S. Leiva is widely distributed at high elevations. Species of Jaltomata have simple, often geminate leaves, 5-merous flowers with rotate to campanulate or tubular corollas, and a bicarpellate ovary housing numerous ovules. The inflorescence is umbellate; anthers dehisce longitudinally and the ovary is girdled by a disk at its base. The berry, orange or red on most South American species and dark purple to black on most Central American species, is not enclosed by the calyx and is often edible (Leiva, 1998; Mione, 1992). The genus includes about 50 herbaceous and shrubby species distributed from Arizona, U.S.A., to Bolivia, with one species each on the Galapagos Islands and Greater Antilles (Mione et al., 1993). These descriptions of three new species are a contribution to ongoing systematic studies of this genus (e.g., Mione, 1999; Mione & Leiva, 1997). MATERIALS AND METHODS The compound light microscope was used for measurement of stalked glands and stigma papillae; flowers placed in 70% ethanol in Peru were used. The sizes of structures as indicated by the scale bars in the figures may differ somewhat from the sizes given in the descriptions because alcohol-preserved flowers were used for drawing, while dried specimens were used for measurements. Seeds of J. lomana were not available for study. Trichomes are not gland-tipped unless indicated as such. Finger hairs are uniseriate, unbranched, and multicellular. Branchlet hairs (Fig. 3B) have multiple termini (Seithe, 1979). A gland-tipped finger hair has a bulbous terminal cell (Fig. 1C) that stains densely with neutral red, as does the multicellular head of a stalked gland (illustrated in Mione & Serazo, 1999). Jaltomata cajacayensis S. Leiva & Mione, sp. nov. TYPE: Peru. Ancash: Bolognesi, highway from Pativilca to Recuay and Huaraz, km 90, town of Cajacay, 2540 m, open sun, roadside with Agave andina and Carica candicans, 18 Jan. 1998, T Mione, S. Leiva G. & L. Yacher 624 (holotype, NY; isotype, CONN). Figure 1. Planta fruticosa; axes juvenes, folia, faciesque abaxialis calycis obtecta pilis indivisis apice glandiferentibus; folia ovata vel deltata, ad 9 cm longitudine, 10 cm latitudine, petiolo ad 3.2 cm longitudine; inflorescentia floribus 14 ut maximum; calyx 13 mm diametro maturitate fructus; corolla brevissime, tubulosa, limbo reflexo 10.3-19.2 mm diametro, olivacea; filamenta villosa secus proximales 4/5 partes longitudinis; bacca aurantiaca, ad 9 mm diametro. Shrub to 1.1 m high. Young axes, peduncles, pedicels, and abaxial faces of calyx villous with erect, gland-tipped finger hairs to 3 mm long. Woody stems glabrous, terete, to at least 1.5 cm diam. Leaves alternate, often geminate, the blade ovate or deltoid, to 9 x 10 cm, pubescence of gland-tipped finger hairs on both faces, the margin repand, sinuate or dentate with up to 5 pairs of broad, rounded teeth; petiole to 3.2 cm long. Inflorescence axillary or less commonly arising from a NovoN 10: 53-59. 2000. This content downloaded from 207.46.13.176 on Fri, 16 Sep 2016 06:00:46 UTC All use subject to http://about.jstor.org/terms