|1.||a place on a road where accidents frequently occur|
|2.||any dangerous or difficult place|
|3.||a disease of roses, Diplocarpon rosae, that causes circular black blotches on the leaves|
common disease of several plants that is caused by species of Pseudomonas bacteria or by many fungus species in the genera Asterina, Asterinella, Asteroma, Diplotheca, Glomerella, Gnomonia, Microthyriella, Placosphaeria, and Stigmea. Infections occur during damp periods and appear as round to irregular black leaf spots, sometimes on petioles, stems, and flower parts
Learn more about blackspot with a free trial on Britannica.com.