Nigrospora

Although sometimes mistaken for a cultivar or clone name due to nomenclature, Nigrospora is actually a fungal plant pathogen that affects cacti. Because it is a microfungus rather than a cactus clone, it does not possess botanical features such as ribs, spines, or a specific epidermis color. Instead, it manifests as an opportunistic infection on host cacti. Affected specimens are often described by growers as looking “diseasey,” though specific visual symptoms on the host's epidermis are not detailed in the community discussion.

Nigrospora is a naturally occurring fungal pathogen and has no breeder, discovery history as a cultivar, or original horticultural source. Its presence in community discussions is documented through reports of infections on host plants, such as those photographed by Hank Radda in 2025 (approx).

Because Nigrospora is a pathogen rather than a cactus clone, cultivation notes focus on preventing infection and treating affected host cacti: * Environmental Management: Prevent infections by minimizing environmental stress. Ensure host cacti are not subjected to drought or nutrient deficiencies (“nutes”), which weaken their natural defenses and allow this weak pathogen to take hold. * Chemical Treatment: If an infection is present, apply fungicides such as chlorothalonil (Daconil) or iprodione. Fungicides containing benzimidazole compounds, thiabendazole, or benomyl are also highly effective.