Morphological differences between violets growing at heavy metal polluted and non-polluted sites

Environmental conditions, especially pollution of soils by heavy metals, can severely affect plant morphology, anatomy and reproduction. In present investigation, the morphological variability of forest violets (Viola reichenbachiana and V. riviniana), their degree of colonization by arbuscular mycorrhizal fungi (AMF) and their reproduction properties were studied using samples from ore-bearing areas with soils rich in heavy metals. In these habitats, individuals with typical morphological characters of V. reichenbachiana and V. riviniana were not identified but populations were intermediate between these two species. Three ore-bearing areas with soils of a high content but low extractable amounts of heavy metals (Pb, Zn, Cd) were covered by anthropogenic pine or beech forests, contrary to typical calamine heaps with metallophyte floras. Violets growing on ore-bearing areas were fully fertile, deposited Pb and Zn mainly in roots and had low Cd levels both in shoots and roots. Plants differed in AMF colonization with the degrees varying from nil to moderate. The violets growing in these areas were not affected in their reproduction and can be considered as stabilized introgressive forms or ecotypes of parental species on these soil conditions.     

Phytochemical and chemotaxonomic studies on Phyllodium pulchellum (Leguminosae)

A phytochemical investigation on the aerial part of Phyllodium pulchellum led to the isolation of 16 compounds including five flavonoids (1–5), three lignans (6–8), four indole alkaloids (9–12), and four other-type compounds (13–16). Their structures were elucidated by their spectroscopic data analysis. Among them, 12 compounds (1, 2, 4–9, and 11–14) are reported from the genus Phyllodium for the first time, while compound 14 was isolated from the Leguminosae family for the first time and compound 11 was firstly reported in the plant kingdom. The chemotaxonomic significance of these compounds was also summarized.     

Phytochemical and pharmacognositc investigation of Bauhinia forficata Link (Leguminosae)

We have isolated two phytoconstituents present in the B. forficata leaves, a medicinal plant employed in folk medicine specially for the treatment of diabetes. These compounds were isolated by column chromatography and identified as beta-sitosterol and kaempferol-3,7-dirhamnoside (kaempferitrin) by spectroscopical data and comparison with authentic samples. A comparative study with different parts of the plant indicated that the latter is present only in the leaves, suggesting that it might be useful for a suitable quality control of phytotherapeutics which contain this organ of B. forficata in its composition.     

Phytochemical and mineral components of foods consumed by black howler monkeys (Alouatta pigra) at two sites in Belize

We analyzed the chemical composition of the diets of eight groups of free‐ranging black howler monkeys (Alouatta pigra) in Belize, Central America. The study groups were located in two different forests: the Community Baboon Sanctuary (CBS) and the Cockscomb Basin Wildlife Sanctuary (CBWS). Two of the study groups were translocated from the CBS to CBWS 3 months into the study, and we compared the diets of groups in the two forests. Young and mature leaves, fruits, flowers, and fig samples (n = 144) were analyzed for water content, crude and available protein, fiber, simple sugars, and minerals. Statistically significant differences were found among the plant parts in all measures except acid‐detergent fiber. Dietary foliage in CBS was higher in water content and protein but lower in simple sugars than dietary foliage in CBWS. We suggest that changes in the selection of plant parts by primates may be related to differences in the nutritional content of those parts. These data may be useful in developing optimal diets for captive howler monkeys. Zoo Biol 19:95–109, 2000. © 2000 Wiley‐Liss, Inc.     

Phytochemical and pharmacological analysis of Bauhinia microstachya (Raddi) Macbr. (Leguminosae)

This paper describes the isolation of four phytoconstituents from the leaves of Bauhinia microstachya, a Brazilian medicinal plant used in folk medicine for the treatment of several ailments. Based on spectroscopic evidence, these compounds were identified as methyl gallate (1), kaempferol 3-O-rhamnosyl (2), quercitrin (3) and myricitrin (4). The crude methanolic extract and two compounds (3 and 4) were tested as analgesic using the writhing test in mice. The extract and compound 3 caused potent and dose-related analgesic effects, confirming the popular use of this plant for the treatment dolorous processes.     

Differences between banded thickets (tiger bush) at two sites in West Africa

Abstract. This paper deals with the influence of edaphic conditions on the spatial structure of banded thickets or tiger bush (brousse tigrée). It is based on two sites in West Africa, with similar climatic conditions but located on contrasting substrates. The spatial structure was described with standardized characteristics including thicket spacing, thicket/inter‐thicket contrast, upslope/downslope asymmetry and species zonation throughout the vegetation band. Recruitment and senescence features of woody stands were emphasized in order to understand current dynamics. Data were collected on transects oriented perpendicular to the contours and so to the thickets as well. A standardized analytical procedure was applied to data from both sites to ensure consistent and thorough delineation of thickets. The overall periodicity of thickets, the woody flora and the dominant species Combretum micranthum were similar at the two sites. However, thicket spacing, thicket/inter‐thicket contrast and upslope/downslope floristic asymmetry of the thickets were higher in the less favourable site. Also seedlings were less abundant, with a greater dependence on pre‐existing thickets. Not all banded vegetation systems show sharp contrasts and are strongly asymmetric, since such characteristics are likely to be reinforced by adverse environmental conditions. As a consequence, current dynamics may be more diverse than expected. Quantified inter‐site comparisons can greatly help to classify African banded vegetation systems and to discuss potential dynamic outcomes.     

A multi-proxy dendroecological analysis of two tropical species (Hymenaea spp., Leguminosae) growing in a vegetation mosaic

Tree species use a variety of strategies to obtain resources. As a result, semi-deciduous forest species and cerrado species can grow in close proximity and in the same climate, while occupying very different vegetation types. The aim of this study was to understand the dynamic responses of Hymenaea courbaril, a forest species, and Hymenaea stigonocarpa, a cerrado species, to annual climatic variation and increasing atmospheric CO₂ concentrations under the same macroclimatic conditions. To that goal, we constructed chronologies of tree-ring width, vessel area, and intrinsic water-use efficiency (calculated from tree-ring δ¹³C content) for Hymenaea trees growing in a mosaic of the two vegetation types. Our analyses revealed that both species responded to climatic variation in similar ways, but with different intensities and at different times of year. Climate models showed that precipitation had a stronger effect on tree-ring width and earlywood vessel area of H. courbaril and temperature was slightly more determinant for H. stigonocarpa. In addition, both species showed increasing intrinsic water-use efficiency over the last five decades, but only individuals with reduced growth rate presented this trend, suggesting that those specimens in favorable growth conditions do not respond to the atmospheric CO₂ enrichment. Despite the trend in water-use efficiency found in some individuals, it did not reflect in a higher growth rate. The differences between the two species documented by us may be due to divergent sources of hydrological stress in the two vegetation types.     

A new species of Mimosa (Leguminosae) from Coahuila,Mexico

Mimosaunipinnata from the Sierra de San Marcos in the Cuatro Ciénegas Basin of central Coahuila, Mexico, is described. It is unique among mimosas in having oncepinnate leaves.     

Acacia sousae (Leguminosae: Mimosoideae) a new species from Mexico

A new species,Acacia sousae, from the states of Guerrero and Puebla is described and illustrated. A key for determination of the related species is given.     

Insight on segregation distortions in two intraspecific crosses between annual species of Medicago (Leguminosae)

 About 40% (α=0.05) of the PCR-derived markers scored in a Medicago truncatula and M. tornata intraspecific cross departed from Mendelian expectations at α=0.05. This proportion is among the highest ever documented in the literature, notably for intraspecific crosses. Estimations of DNA amount were also implemented for the parental genotypes or parental lines, and significant variations were observed. Our results suggest that the parental genotypes have diverged for quite a while, and we propose that the level of distortion we documented is correlated with the genome size difference we measured. Received: 11 April 1996 / Accepted: 27 September 1996     

Calliandra dolichopoda and C. cualensis (Leguminosae, Mimosoideae), two new species from Mexico

Calliandra dolichopoda and C. cualensis, two species endemic to Guerrero and Jalisco, Mexico, respectively, are described and illustrated. Both species appear to be closely related to C. hirsuta.

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Resumen  Se describen e ilustran Calliandra dolichopoda y C. cualensis, dos especies endémicas de Guerrero y Jalisco, México, respectivamente. Ambas especies parecen estar relacionadas con C. hirsuta.

     

Studies in Stryphnodendron (Leguminosae: Mimosoideae) including two new taxa

Stryphnodendron campestre Forero andS. guianense (Aubl.) Benth. ssp.glandulosum Forero are described and illustrated, and notes on the nomenclature ofS. adstringens and on the exclusion ofS. colombianum from the genus are included.     

Two new Marina (Leguminosae) from the southern Baja California peninsula, Mexico

Marina victoriae andM. brevis are newly described species from the southern Baja California peninsula, Mexico. The former is a perennial herb locally abundant in the eroded hillsides at the foothills of Sierra de la Victoria, where an oak woodland and a dry tropical forest meet. The latter is an elusive ephemeral inhabiting a narrow strip of land between the mangroves and the desert scrub on an island in the Gulf of California. These two new species belong to the seriesChrysorrhizae, a group native to the Gulf of California basin.     

Recurring attacks by white sharks on divers at two Pacific sites Mexico and California

Synopsis Two pairs of recurring attacks by white sharks on divers are detailed. A free-diving spearfisherman was fatally injured at Isla de Guadalupe, Mexico. Eleven years later, a second free diver was attacked while spearfishing at the same location. The swim fin of a commercial abalone diver was bitten at Point Conception, California, and an abalone sport scuba diver was attacked at the same site only four days later. The possible existence of attack prone microsites, perhaps characterized by the presence of pinnipeds and the absence of canopy-forming vegetation, is considered. The use of wound characteristics related to tooth interspace measurements for determining the causal species and approximate shark size is discussed. Diver safety recommendations and precautions are highlighted.     

Symptomatic differences between the sexes in rural Mexico

This paper addresses the problem of the differential presentation of illness by women and men in two Spiritualist temples and a physician's office situated in rural Mexico. Women's morbidity raises the broader anthropological questions of the interplay between symptomatic expression and women's unequal status in the social structure, their cognitive evaluation of specific life experiences, cultural etiological explanations and Western models of dysphoria. Symptoms presented by patients in different health care delivery sites are compared and case vignettes of patients' illnesses and attributions are presented to demonstrate the ways in which culturally constructed illness attributions and illness expressions comprise a somatic grammar for the articulation of experiential distress. The sick population is compared with a control group of healthy women to highlight the socio-cultural and psychosocial variables that promote illness in women from the same sociocultural strata of rural Mexico. Collective understandings of the role of life events and emotional expression in illness attributions legitimize somatization as a coping style under adverse existential conditions.     

Interspecific hybridization between diploid species of Lotus (Leguminosae)

An interspecific hybridization study has been carried out between seven diploid species of Lotus (L. alpinus Schleich., L. japonicus (Regel) Larsen, L. filicaulis Dur., L. schoelleri Schweinf., L. krylovii Schischk. and Serg., L. tenuis Waldst. et Kit., and L. corniculatus var. minor Baker) closely related to L. corniculatus L. A total of 139 interspecific hybrids were produced in 16 combinations of the 7 species. Nine of these crosses were produced for the first time and four were obtained by means of embryo-culture. The growth habit, number of florets per umbel, flower color expression, HCN reaction and 15 metrical traits were compared between parents and hybrids. The relative case with which some hybrids were produced suggested that during the early evolutionary history of the genus species diversification could have originated through interspecific hybridization and subsequent gene differentiation. In some crosses, the hybrids resembled one parent more closely than the other. This close morphological affinity between the hybrids and one of their parents would make it extremely difficult to detect such hybrids in natural populations and probably aceounts for the prevailing belief that there is little or no hybridization in nature.     

New species of dalea section parosela (Leguminosae: Amorpheae) from Peru and Mexico

Dalea (ser.Coeruleae) strobilacea from Cajamarca and La Libertad, Peru and D. (ser.Versicolores) daucosma from Nay arit, Mexico are described, compared with kindred, and illustrated.     

A new species of astragalus (Leguminosae) from northwestern New Mexico and adjacent Arizona

Astragalus chuskanus Barneby & Spellenberg, a new species of ser. Humistratae, is described, figured, discussed, and inserted into current monographic keys to the genus.     

Genetic diversity and structure of the endemic Caesalpinia hintonii complex (Leguminosae: Caesalpinioideae) in Mexico

The Caesalpinia hintonii complex is formed by five endemic species (C. hintonii, C. laxa, C. macvaughii, C. melanadenia and C. epifanioi) occurring in central Mexico. This species complex is under incipient genetic divergence as by-product of local adaptations in reproductive and morphological traits to different habitats. We estimate the genetic variation and structure of populations of this species complex to assess the extent of genetic differentiation among populations and related species along its geographic distribution. Estimations of genetic diversity and structure were done based on ten enzymes and 18 loci. Mean number of alleles per locus ranged from 1.5 to 1.9. Polymorphic loci ranged from 42.1 to 68.4. Observed (H_o: range 0.191–0.275) and expected (H_e: range 0.205–0.317) heterozygosities in this complex were higher compared with other endemic and legume species. Neis genetic diversity estimates showed that most genetic variation was found within (H_S = 0.325) rather than among populations (D_ST = 0.085). Populations of the species C. hintonii showed a considerable genetic differentiation (F_ST = 0.207). The results of genetic diversity and structure within and among populations are in accord with the great morphological differentiation described for this species complex.