Clarkia (Onagraceae) is a genus of 42 annual species, mostly native to California, that has served as a model for many studies of plant evolutionary biology, particularly morphological, cytological, and genetic divergence; reproductive isolation; and speciation. Section Sympherica is the largest section with eight diploid and one allotetraploid species. Species in the section have provided impo...

An investigation was carried out at the Muda rice fields, Peninsular Malaysia during four consecutive seasons of 2004 and 2005 to study the seasonal variation in the weed seedbank. Species composition with their dominance ranking and similarity between the species were recorded. A total of 577 seeds/sample (3337 seeds/m ) in 1/2004, 970 seeds/sample (5659 seeds/m ) in 2/2004, 928 seeds/sample (...

This study was designed to characterize the interactions between Ludwigia elegans flowers and visiting bees during two years in two areas 200 km apart, at the same latitude (approximately 22 masculine 48'S) but at different altitudes (Alumínio, 600 m, and Campos do Jordão, 1500 m), in the State of São Paulo, Brazil. As these flowers open simultaneously in the morning and lose their petals by su...

The effects of salt stress on freshwater plants has been little studied up to now, despite the fact that they are expected to present different levels of salt sensitivity or salt resistance depending on the species. The aim of this work was to assess the effect of NaCl at two concentrations on three invasive freshwater species, Elodea canadensis, Myriophyllum aquaticum and Ludwigia grandiflora,...

Ten plant extracts commonly used by the Meru community of Kenya were evaluated for the in vitro antiplasmodial, in vivo antimalarial, cytotoxicity and animal toxicity activities. The water and methanol extracts of Ludwigia erecta and the methanol extracts of Fuerstia africana and Schkuhria pinnata exhibited high antiplasmodial activity (IC(50) < 5 microg/mL) against chloroquine sensitive (D6) a...

Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to prevent them from entering a country. However, many related species are commercially traded, and distin...

Macroinvertebrados associados a macrófitas aquáticas tornam-se mais abundantes, pois as características morfológicas dessas plantas contribuem para o aumento da sua colonização, diversidade e avaliação qualidade ambiental. Esse estudo apresenta levantamento composição riqueza de macroinvertebrados (Classe Insecta) diferentes espécies avalia água do reservatório Tanque Aroeiras, Caetité, Bahia. ...

Contaminants such as nutrients, metals, and pesticides can interact with constructed wetlands and existing drainage ditches used as agricultural best-management practices. Our research has shown that the presence of macrophytes and a hydrologic regime aid in the transfer and transformation of pesticides associated with agricultural runoff. This study consisted of application of both atrazine (t...