Pollen, charcoal, magnetic susceptibility, and bulk density data provide the first paleoecological record spanning the last 33,000 years from the western cordillera of the Peruvian Andes. Sparse super-puna vegetation existed before 30,000 cal yr B.P. around Lake Compuerta (3950 m elevation), prior to a sedimentary hiatus that lasted until c. 16,200 cal yr B.P. When sedimentation resumed, a glac...

ABEYSEKERA, R. M., NEWCOMB, W . , SILVESTER, W. B., and TORREY, J. G. 1990. A freeze-fracture electron microscopic study of Frankia in root nodules of Alnus incana grown at three oxygen tensions. Can. J. Microbiol. 36: 97-108. Nodulated plants of Alnus incana ssp. rugosa and ssp. incana were grown with the roots exposed to 5,21, and 40 kPa 02. The nodules were studied by freeze-fracture transmi...

Pollen monitoring was carried out in Lublin in 2001-2012 by the volumetric method using a Hirst-type spore trap (Lanzoni VPPS 2000). Daily pollen concentrations considerably differed in the particular years. The pollen counts with the biggest variability were observed in the first half of a year when woody plants flowering. The highest annual pollen index were noted for the following taxa: Betu...

SILVESTER, W. B., SILVESTER, J. K. , and TORREY, J. G. 1988. Adaptation of nitrogenase to varying oxygen tension and the role of the vesicle in root nodules of Alnus incana ssp. rugosa. Can. J . Bot. 66: 17721779. Growth of Alnus incana ssp. rugosa plants with root systems at Po2 levels of 5 , 21, and 40 kPa showed no significant differences among treatments over a 6-week period. Nitrogenase ac...

Alnus maritima and Alnus serrulata are riparian shrubs that occur in similar habitats in the southern and eastern United States.Alnus serrulata is abundant throughout this range, but A. maritima is rare, occurring only in small populations in Oklahoma and Georgia and on the Delmarva Peninsula. Alnus maritima is more resistant than A. serrulata to water and temperature stresses, but the degree t...

Bisbenzylisoquinoline (BBIQ) alkaloids are a diverse group of natural products that demonstrate range biological activities. In this study, the in vitro antiplasmodial activity three BBIQ (cycleanine [compound 1], isochondodendrine 2], and 2?-norcocsuline 3]) isolated from Triclisia subcordata Oliv. medicinal plant traditionally used for treatment malaria Nigeria studied alongside two semisynth...