Scanning electron microscope analysis of cut rose stems revealed several types of vascular occlusions after 5 to 10 days in either water or sucrose solutions at 18°C. The number of tracheids which exhibited “blocking” at floral senescence was less than 4%. The incidence of vascular “blocking” was equivalent at the stem base, water line and neck. Breakdown of secondary tissue in the xylem was observed more frequently than other types of occlusions, but appeared only after at least 5 days. Occasionally, “blocking” materials were found protruding through the pits and end plates of tracheids. Exudate, which occasionally clogged conducting tissue at the stem base, apparently came from the phloem at the time of harvest. Other exudates, which dried immediately during the process of cutting cross sections, formed crystals which could be misinterpreted as “blocking” materials. Some tracheids in stems held in a 2% sucrose solution developed occlusions with fungal and bacterial growth or “slime plugs”. A progressive breakdown of the secondary thickening of the tracheids was found as the rose senesced. Neither leaf removal nor placement in sucrose solutions influenced the number of occlusions. The occlusions were much larger, however, after 3 days in 2% sucrose or 5-10 days in water.