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Symplocarpus L. (Araceae) is a disjunct genus including S. foetidus (L.) Nutt. var. latissimus (Makino) S. Hara, S. nipponicus Makino, and S. nabekuraensis Otsuka & K. Inoue in temperate eastern Asia; S. egorovii N. S. Pavlova & V. A. Nechaev in the Russian far east; and S. foetidus (L.) Nutt. in temperate northeastern North America. For the first time, pollen morphology of Symplocarpus was investigated by light and scanning electron microscopes. Symplocarpus foetidus var. latissimus and S. foetidus had reticulate surfaces and rounded (obtuse), long, equatorial axis tips, whereas S. nipponicus had microreticulate surfaces and acute tips. Symplocarpus foetidus in North America had larger pollen grains than S. foetidus var. latissimus in eastern Asia. Thus, based on pollen characteristics, S. foetidus var. latissimus is more closely related to S. foetidus than to S. nipponicus. Other lines of evidence, such as molecular phylogenetic studies and phenology, support the phylogenetic relationships among these species proposed in this study. The slightly modified acetolysis procedure conducted in this paper is a promising application to study weak exine or exineless pollen grains. [ABSTRACT FROM AUTHOR]

Deokjeok Island is located off the west coast of the Korean Peninsula and is a suitable place to monitor the long-range transport of air pollutants from the Asian continent. In addition to pollutants, Asian dust particles are also transported to the island during long-range transport events. Episodic transport of dust and secondary particles was observed during intensive measurements in the spring (March 31-April 11) and fall (October 13-26) of 2009. In this study, the chemical characteristics of long-range-transported particles were investigated based on highly time-resolved ionic measurements with a particle-into-liquid system coupled with an online ion chromatograph (PILS-IC) that simultaneously measures concentrations of cations (Li+, Na+, NH4+, K+, Ca2+, Mg2+) and anions (F-, Cl-, NO3-, SO4 2-). The aerosol optical thickness (AOT) distribution retrieved by the modified Bremen Aerosol Retrieval (M-BAER) algorithm from moderate resolution imaging spectroradiometer (MODIS) satellite data confirmed the presence of a thick aerosol plume coming from the Asian continent towards the Korean peninsula. Seven distinctive events involving the long-range transport (LRT) of aerosols were identified and studied, the chemical components of which were strongly related to sector sources. Enrichment of acidic secondary aerosols on mineral dust particles, and even of sea-salt components, during transport was observed in this study. Backward trajectory, chemical analyses, and satellite aerosol retrievals identified two distinct events: a distinctively high [Ca2++Mg2+]/[Na+] ratio (>2.0), which was indicative of a preprocessed mineral dust transport event, and a low [Ca2++Mg2+]/[Na+] ratio (<2.0), which was indicative of severe aging of sea-salt components on the processed dust particles. Particulate Cl- was depleted by up to 85% in spring and 50% in the fall. A consistent fraction of carbonate replacement (FCR) averaged 0.53 in spring and 0.55 in the fall. Supporting evidences of Cl- enrichment on the marine boundary layer prior to a dust front were also found. Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of the Air & Waste Management Association for sector and air mass classifications of clean and LRT cases. [ABSTRACT FROM AUTHOR]