Spirodela polyrhiza (L.) Schleid. (Lemnaceae): primera cita para Galicia (NO de la Península Ibérica)

La familia Lemnaceae Martinov incluye monocotiledóneas propias de aguas continentales que viven flotando libremente o sumergidas. Se trata de un grupo de plantas que, debido a su reducido tamaño y particular morfología, presentan una compleja taxonomía lo que dificulta su identificación. Esta familia comprende 6 géneros de los que tres −Lemna L., Spirodela Schleid. y Wolffia Horkel ex Schleid− han sido citados para la Península Ibérica (Galán de Mera & Castroviejo, 2007). En Galicia, hasta el momento, sólo viven dos especies de Lemna: L. minor L., en las cuatro provincias gallegas y L. giba L., esta última únicamente en Lugo y Ourense

Are diversification rates and chromosome evolution in the temperate grasses (Pooideae) associated with major environmental changes in the Oligocene-Miocene?

The Pooideae are a highly diverse C3 grass subfamily that includes some of the most economically important crops, nested within the highly speciose core-pooid clade. Here, we build and explore the phylogeny of the Pooideae within a temporal framework, assessing its patterns of diversification and its chromosomal evolutionary changes in the light of past environmental transformations. We sequenced five plastid DNA loci, two coding (ndhF, matk) and three non-coding (trnH-psbA, trnT-L and trnL-F), in 163 Poaceae taxa, including representatives for all subfamilies of the grasses and all but four ingroup Pooideae tribes. Parsimony and Bayesian phylogenetic analyses were conducted and divergence times were inferred in BEAST using a relaxed molecular clock. Diversification rates were assessed using the MEDUSA approach, and chromosome evolution was analyzed using the chromEvol software. Diversification of the Pooideae started in the Late-Eocene and was especially intense during the Oligocene-Miocene. The background diversification rate increased significantly at the time of the origin of the Poodae + Triticodae clade. This shift in diversification occurred in a context of falling temperatures that potentially increased ecological opportunities for grasses adapted to open areas around the world. The base haploid chromosome number n = 7 has remained stable throughout the phylogenetic history of the core pooids and we found no link between chromosome transitions and major diversification events in the Pooideae.España, Ministerio de Ciencia y Tecnología CGL2006-00319, CGL2009-12955-C02-0

Novas aportacións á orquideoflora da Serra do Courel (Galicia, NW Península Ibérica)

In this study, the find of two new orchids at Serra do Courel is commented. These data improve knowledge about the F. Orchidaceae in this area and, therefore, in Galicia and the Iberian Peninsula.Neste traballo coméntase o achádego de dúas novas especies de orquídeas na Serra do Courel. Estes datos complementan a información existente da Familia Orchidaceae nesta serra e no contexto global de Galicia e a Península Ibérica

Distribución de Spiranthes spiralis (L.) Chevall (Orchidaceae) en Galicia (NO de España): Análise de parámetros ambientais

Spiranthes spiralis is a widespread orchid in Europe that has suffered an important regression in the last few years. The aims of this study were to analyse the status of the Galician populations of S. spiralis, to characterize the environmental conditions in which this species grows and to identify possible reservoirs for the taxon. To achieve our aims we compared published data gathered from the literature with information collected from official herbaria (SANT and MA). We also explored new areas and prepared maps correlating the distribution of the populations with different environmental variables (average annual temperature, precipitation and soil type). In our field surveys we found 20 new populations (40% of the total of populations considered) in 13 different municipalities. Roughly 70% of the populations grow in areas where the average annual temperature is 15.0 ºC and the annual precipitations are 1300 mm. The results indicate that the number of detected populations of S. spiralis in Galicia has grown in recent years; nevertheless, a long term study on population sizes, genetic diversity and habitat characterization is needed to establish its conservation status.Spiranthes spiralis é unha orquídea considerada común en Europa pero que nos últimos anos sufriu unha importante regresión. Os obxectivos deste estudo foron analizar o estado das poboacións galegas de S. spiralis, caracterizar as condicións ambientais nas que se desenvolve e identificar posibles reservorios da especie. Para acadalos  comparáronse os datos previos publicados coa nova información existente nos herbarios oficiais (SANT e MA), exploráronse novas áreas e elaboráronse os mapas de distribución das poboacións con respecto a distintas variables ambientais (T media anual, precipitacións e tipo de solo). Nas prospeccións realizadas atopáronse 20 poboacións novas (40% do total) en 13 concellos distintos. Aproximadamente o 70% das poboacións medran en áreas onde a temperatura media anual é de 15,0 ºC e as precipitacións anuais superiores a 1300 mm. Os resultados obtidos indican que aínda que aumentou o número de poboacions de S. spiralis en Galicia o tamaño poboacional observado e os tipos de hábitat nos que a especie se desenvolve requiren un estudo a máis longo plazo no que sería necesaria a realización de análises xenéticas para estabelecer o grado de conservación da especie en Galicia