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FivePythiumspecies are recorded for the first time in South America. Morphological and phylogenetic analyses (LSU and ITS rDNA regions) confirmed the identification ofP. grandisporangium, P. kashmirense, P. oopapillum,P. segnitiumandP. takayamanum. Moreover, this is the second record ofP. takayamanumin the world. The species were isolated from different samples, such as soil, seawater, substrates used in hydroponics and roots of hydroponic crops in Brazil. The asexual reproduction ofP. segnitiumis documented for the first time and detailed descriptions and illustrations of all species are provided.

The distribution of Rhizophlyctis roseawas examined in soils from 22 locations including disturbed and undisturbed habitats in eastern Australia. Thalli of Rh. roseawere observed on baits from 60% of the sites (67% agricultural and 33% natural soils). Within the disturbed habitats, samples from four sites that experience different temperature ranges were assessed for frequency, abundance, number of thalli and density of colonization of the baits. Lens paper baits were placed into Petri dishes with sterile deionized water and air-dried soil and incubated for up to four days at 20, 35 or 40°C, and at 20°C after freezing (−15°C) and heating (80°C) the soil. The abundance, frequency, number of thalli and density of colonization varied among the samples analysed, with the greatest abundance, number of thalli and density for Pitt Town Bottoms and the highest frequency for Pitt Town Bottoms and Narrabri soils. All isolates grew and released zoospores after heat and freezing treatments. Freezing soil before baiting increased the number of thalli and density of colonization of baits, while heating decreased the frequency and abundance of Rh. rosea.

A study of soil samples was carried out at five contiguous habitats of different vegetation types from the Reserva Natural Selva Marginal Punta Lara (Buenos Aires, Argentina): coast, dry forest, floodplain marsh, grassland and marginal forest. Soil samples were processed with a baiting technique, thus producing an inventory of twenty four saprophytic organisms belonging to the Blastocladiomycota, Chytridiomycota and Oomycetes. The frequency analysis showed that all species were of rare occurrence on a macro scale although there were distributional differences between habitats. Cluster analysis showed three groups: (i) the marsh and the grassland, (ii) the dry and the marginal forests and (iii) the coast, which appeared to be the poorest habitat with only three isolations and two taxa recorded.