sentences:  Closely related species – namely "R. pepo" and "R. nectarix" – cause symptomatically similar diseases, but distinguishing between species can be quite difficult without the help of molecular (DNA) analysis, since survival structures are rarely observed in both the field and laboratory.Species in the genus "Rosellinia" can be microscopically identified by the characteristic pear-shaped (piriform) swelling near the septa of adjacent hyphal cells.Taxonomically, "Rosellinia" spp.