Pseudomonas viridiflava is a bacterium that has been claimed to cause disease in hellebores in New Zealand, among other plants. The bacterial disease manifested on hellebore plants in the form of black leaf spots, necrosis petal, and stem lesions. The most popular ornamental and commercial crop grown in New Zealand is "Helleborus orientalis" and its hybrids, of which 90 percent of the "H. orientalis" in the Tauranga nursery contracted the disease after several days of moderate rainfall. The disease caused discoloration in the form of black leaf spots that were circular and about 1.5–2mm in diameter, black stem lesions, and dry, grey to brown lesions with distinct margins on the flower petals. The symptoms were different from other leaf-spotting hellebore diseases, such as those caused by the fungus "Coniothyrium" and the bacteria "Xanthomonas" The case in New Zealand is the only reported case of "P. viridiflava" infecting hellebores so far, but in other plants "P. viridiflava" has been reported to also induce symptoms such as leaf rot, leaf blotch, stem necrosis and blossom blight.