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Jatropha curcas is a native Mexican plant, distributed in the forests of coastal regions; it has shown potential for the production of biofuel, and its raw protein can be used as animal feed. Nevertheless, its current varieties have low yield and production variability, as it is in domestication period. The knowledge of the pollen grains is fundamental for studies of Jatropha reproductive biology and breeding for genetic improvement to generate new hybrids and improve fruit and seed yield. This study compared pollen morphology of four Jatropha species, which include two varieties of J. curcas (one toxic from India and one non-toxic from Mexico), and two varieties of wild J. cinerea (Sinaloa and Baja California Sur); additionally, pollen was collected from wild J. platyphylla (Sinaloa) and J. vernicosa (Baja California Sur) to characterize them palynologically. We used a scanning electron microscope to describe the size and shape of pollen grains. Pollen grains were observed spheroidal. The diameter of the varieties of toxic and non-toxic J. curcas and that of J. platyphylla were 58 ± 2.3, 54 ± 1.7, and 51 ± 2.4 μm, respectively; the number of clavae was 84 ± 10, 108 ± 15, and 180 ± 15.5, respectively. Pollen grains of J. cinerea (Sinaloa) had a diameter of 50 ± 1.7 μm and 220 ± 14 clavae by area; J. cinerea (Baja California Sur) had a diameter of 45 ± 1.9 μm and 195 ± 14.7 clavae. Pollen grains of J. vernicosa had a diameter of 46 ± 2.1 μm and 231 ± 25.6 clavae. The ornamentation of the exine showed clava with capita gemma shaped for varieties of J. curcas species and clavum shaped for J. platyphylla, J. cinerea and J. vernicosa species. The studied varieties have a cross-linked endexine and ectexine intectate. Luminal bacules were observed in the reticular space of J. curcas varieties while none were present in the varieties of J. cinerea, J. platyphylla, and J. vernicosa. [ABSTRACT FROM AUTHOR]

In the arid and semiarid region of Mexico, data on three native grasses growing in diverse ecological environments--Muhlenbergia peruviana (P. Beauv.) Steud., in temperate forests; Bouteloua gracilis (Kunth) Lag. ex Griffiths, in grasslands; Muhlenbergia porteri Scribn. ex Beal, in xeric regions; and one introduced nonnative species, Melinis repens (Willd.) Zizka (Zizka rose Natal grass)--were used in our essay analyzing their potential distribution, based on climatic factors. We took presence-only data applied to the Bioclim algorithm included in the Diva-GIS program. Using database bioclimatic WorldClim-Global Climate Data allowed us to make predictions of the distribution, and to determine the climatic characteristics that each species needs to grow. It generated a potential distribution of the four species under study, concluding that this method can be applied to other grass species from this geographic area in order to improve: a) knowledge of the actual distribution of species in their natural environment, b) knowledge related to biodiversity, and c) to create an indicator to support decisions related to conservation and management of grasses in Mexico. We concluded that possibly climatic requirements prevent the expansion of the introduced species (Zizka rose, Natal grass). [ABSTRACT FROM AUTHOR]

The geographic and host distributions of Arceuthobium hondurense and A. nigrum (Viscaceae) in southern Mexico and Central America have remained unclear due to difficulties in their identification. This study was conducted to clarify the morphology, phenology, distribution, and host affinities of these dwarf mistletoes. Morphological measurements were made for these species across their geographic distributions and nr ITS sequences were generated and compared from selected populations in Mexico. Although subtle, interspecific differences in plant morphology were found, A. hondurense and A. nigrum can be differentiated by the dimensions of their staminate spikes, staminate flowers, and fruits. Our data also indicated that A. hondurense and A. nigrum were not sympatric. Arceuthobium hondurense is distributed from northern Nicaragua to northern Oaxaca, Mexico and A. nigrum is distributed from Veracruz to northern Durango. Although A. hondurense and A. nigrum flowered in the fall, A. hondurense consistently peaked in September and A. nigrum peaked in October, extending into January in central Mexico. A spring flowering period reported previously for A. nigrum was not observed. Additional information on the host distribution and molecular differences of these dwarf mistletoes is also presented. [ABSTRACT FROM AUTHOR]

New localities of geographic distribution for two grasses of Mexico are presented. Muhlenbergia filiculmis Vasey, a species known only in the West of United States is registered for the first time in Mexico. So is the distribution of Distichlis eludens (Soderstr. & H.F. Decker) H.L. Bell & Columbus, is expanded into a regional level, since it has been recently collected in Zacatecas, Mexico. [ABSTRACT FROM AUTHOR]

The genus Abies has about 40 species, which are mainly distributed in boreal or subalpine areas. In Mexico as a diversity center for this genus, all eight species of Abies are protected. Six of them are endemic and mainly distributed in the Sierra Madre Occidental and Oriental. The often isolated relict Abies durangensis Martínez, also known as Durango Fir, is located in the states of Durango, Chihuahua, Sinaloa, and Jalisco and usually grows on slopes with well-drained and shallow lithosols, where the climate is humid and cool. A. durangensis is specifically associated with species such as Pseudotsuga menziesii, Pseudotsuga lindleyana, Pinus strobiformis, Picea chihuahuana, Pinus durangensis, Cupressus lusitanica (lindleyi), and Juniperus deppeana. In the state of Durango, the species has a restricted geographic distribution between 23.2° and 25.7°N and 105° to 107°W and elevations varying from 2,195 m to 2,955 m (mean 2,690 m). The species' habitat has a mean annual temperature that ranges from 8.6 °C to 12.2 °C (mean 10.6 °C) and a mean annual rainfall of 1,088 mm to 1,395 mm (mean 1,224 mm). According to the Red List of Threatened Species of the International Union for Conservation of Nature and Natural Resources, the species is in low risk and does not depend on conservation efforts. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article discusses a study which described new species of Urochloa (U.) from Western Mexico, including U. olivacea and U. pauciflora. Particular focus is given to the characters of Urochloa and Brachiaria. It notes that U. olivacea is an annual plant rooting at the lower nodes. Its sheaths are also shorter or longer than the internodes. Whereas, U. pauciflora is an annual plant with shorter sheats and exposed nodes. Also included are data on distribution, phenology and etymology.

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents the accepted names of oaks in Mexico and neighbouring countries, together with their natural distribution by state. It claims that the distribution data are derived from a report generated from the website http://www.oaknames.org. They include Quercus acherdophylla, Quercus aculcingensi, Quercus acutifolia, and Quercus acutangula.

The article discusses the inventory, use, and distribution of genus Quercus in Tixtla de Guerrero, Mexico. It cites the most important oak species ecologically including Q. magnoliifolia, Q. liebmannii, and Q. acutifolia. It also talks about the economic importance of the oaks of the community of La Estacada. It concludes that the Mexican oak forest is composed of seven species and one variety and the habitats of the species are tropical and deciduous.

El artículo enfoca en la familia de plantas herbáceas, sufrútices, arbóreas o bejucos, Campanulaceae y su subfamilia Lobelioideae que juntos incluyen aproximadamente 76 géneros. Para la familia y subfamilia se indican las características morfológicas y anatómicas, se describe su distribución geográfica y se discurre sobre su presencia en la región de Veracruz, México.

The article describes the bulb species discovered during the 30-day expedition to Southern Mexico in Winter 2008. A stop at San Louis Potosi showed Tillandsia tortilis growing on pine and oaax trees, and Echeveria agavoides on more hospitable ground. Hechtia matudae and Tillandsia susperinsignis were found on the states of Morelos and Mexico. Meanwhile, on the pine and oak forests, Tillandsia eizzi and Tillandsia ponderosa were discovered.

The genus Polianthes (Agavaceae) is endemic to Mexico and is important at the scientific, economical, and cultural level since prehispanic times. Habitat destruction is one of the main factors affecting populations of Polianthes species, yet little is known about the geographic distribution of this genus, and thus its vulnerability to habitat change. We compared three different approaches to measure the Polianthes species area of distribution to assess the risk of species extinction applying the MER (Method of Evaluation of Risk extinction of wild species for Mexico): area of occupancy, extent of occurrence, and ecological modeling. We also found the richness areas of distribution of this genus. We compared the species distributions with Terrestrial Protected Regions (TPR) and Natural Protected Areas (NPA). Although the three methods used to calculate the species area of distribution agree about the highly restricted nature of Polianthes species. The area of occupancy sub-estimate the species distribution, while the extent of occurrence over-estimate it for species with disjoint distribution. Thus, we recommend the use of ecological modeling to improve the assessment of the current species distribution area to apply the MER. Most Polianthes species are distributed in the Sierra Madre Occidental and Transvolcanic Belt. Three species do not occur in any of the NPA or TPR, one species has suitable habitat in three TPR but has not been recorded there, and one species, P. palustris, is likely extinct. .KWT-Keywords: [ABSTRACT FROM AUTHOR]

Copyright of Tropical Ecology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We report, for the first time, the presence of Nierembergia angustifolia in the state of Jalisco, Mexico. The distinctive characteristics of this species and an update of its known geographical distribution are discussed. [ABSTRACT FROM AUTHOR]

The genus Ceratozamia contains more than 20 species distributed in eastern and southern Mexico, with extensions into Central America. Morphology, anatomy, and molecular (ITS) data allow resolution of some aspects of species relationships, provide correlations with ecology, and suggest phytogeographic hypotheses. Some species complexes, such as those centered around C. norstogii and C. miqueliana, are restricted to southernwest Mexico, in what are regarded as Pleistocene floristic refugia. The low level of divergence of ITS sequences among taxa to the north of the Trans-Mexican Neovolcanic mountain range suggests a pattern of recent, and perhaps rapid, speciation. [ABSTRACT FROM AUTHOR]

A phytosociological study of 59 relevés was carried out at Laguna Quila, National Park Lagunas de Zempoala, México, using the Zürich-Montpellier approach. Eleven communities were identified and described. A distinction was made between a submerged and a helophytic hydroseral vegetation. A pronounced humidity gradient was identified in a north-south direction, and also a continuous desiccation was observed. A vegetation map scale 1:1900 is included. 21 families of vascular plants including 41 species and 33 genera have been identified. Families best represented include Cyperaceae with seven species and Ranunculaceae with four species. Phytogeographical analysis on the generic level revealed that the temperate component reached 65%, the cosmopolitan 30% and the tropical 5%. The species of Laguna Quila have a wide distribution in Mexican hydroseries and elsewhere in temperate America. Aquatic and semi-aquatic communities are vanishing rapidly in Mexico, and it is important to understand the dynamics for adequate management of this natural resource. In order to protect this lake it is recommended to control the water extraction of the laguna, to exclude cattle and other activities who can affect indirectly Laguna Quila. [ABSTRACT FROM AUTHOR]

Two species of Valeriana of apparently very restricted distribution are described as new. V. emmanuelii, collected in two localities of the southern extreme of the municipality of Morelia, Michoacán, is related to V. retrorsa Fern. and to V. densiflora Benth. V. zamoranensis belongs to the series Ceratophyllae and is only known from the highest part of Cerro Zamorano; it seems to be related to V. zapotecana Barrie and to V. otomiana Barrie. [ABSTRACT FROM AUTHOR]

Population size distributions were examined for 12 species of trees co-occurring at Chamela Biological Station in Jalisco, Mexico. Species had been selected as congeneric pairs and trios similar in gross morphology and ecology in order better to identify correlates of relative abundance. Rarer species were found unanimously to have more irregular distributions of individuals among size classes than more common species when distributions were compared to a smooth, descending curve constructed from population mean stem diameters (an exponential distribution). Examination among species of patterns of deviation from these corresponding smooth distributions indicates that the most reasonably inferred cause for the observed pattern is consistent differences in degree of fluctuation in recruitment into adult size classes. These results thereby suggest a demographic difference between locally rarer and more common species that may be generally associated with observed differences in relative abundance and indicate a focus for management of rarity in forest trees. [ABSTRACT FROM AUTHOR]

We report, for the first time, the presence of five species of Solanum for the Bajío and neighboring regions flora. Solanum brachistotrichum, S. hintonii, S. jamesii y S. morelliforme are grouped in Solanum section Petota while S. triquetum is part of Solanum section Dulcamara. We highlight the distinctive characteristics of each species and update their known geographical distribution. Finally, we present a drawing of S. triquetrum. [ABSTRACT FROM AUTHOR]

A check list of vascular plants consisting of 89 families, 208 genera and 288 species is presented. The study area, called Sierra de Nanchititla, is located in the southwestern region of the State of Mexico, near the borders with Guerrero and Michoacán. The families Asteraceae, Pteridaceae, Burseraceae, Fabaceae, Mimosaceae and Rubiaceae are best represented. Geographical distribution of families and genera is analyzed. The elements of tropical affinity are dominant. Complementary data on phenology of some life forms are provided as well as information about the state of conservation of original vegetation. [ABSTRACT FROM AUTHOR]

Commelina nivea López-Ferrari, Espejo et Ceja, and Commelina rzedowskii López-Ferrari, Espejo et Ceja, two white flowered species are described and illustrated in this paper. The former is known only from Las Adjuntas, municipio of Pueblo Nuevo in the state of Durango and the other was collected in the neighborhood of Tenería, municipio of Tejupilco in the state of México. [ABSTRACT FROM AUTHOR]

The present status of the floristic-ecological knowledge of wild Mexican Iridaceae is defined. 16 genera and 98 species of Iridaceae, all of them belonging in the 4 tribes of the subfamily Iridoideae are registered from the country. The tribe Tigridieae has its principal center of radiation in Mexico, where 11 of 18 genera and 52 of approximately 130 species grow; of those, 3 genera (30 %) and 38 species (71.7 %) are endemic. One naturalized species is also known. The best represented genera of Iridaceae in Mexico are Sisyrinchium (40 spp.) and Tigridia (29 spp.). Endemism in the family at species level reaches 54.6 %. Data and comments on habitat, distribution and phytogeography of Mexican Iridaceae are included. [ABSTRACT FROM AUTHOR]