A fungus in the genus Taphrina often attacks the plums; the young ovaries swell, often much larger than full grown plums, become hollow and often persist on the tree in winter.
Prunus | Sambucus nigra | Centaurea nigra | Prunus avium | Pinus nigra | Prunus cerasus | Juglans nigra | Prunus subg. Padus | Fraxinus nigra | Carex nigra | Brassica nigra | Prunus serotina | Prunus salicina | Prunus pensylvanica | Prunus mume | Populus nigra | Tinea nigra | Prunus virginiana | Prunus tenella | ''Prunus'' subg. ''Padus'' | Prunus padus | Prunus mexicana | Prunus maritima | Prunus laurocerasus | Prunus japonica | Prunus fruticosa | Prunus emarginata | Prunus caroliniana | Prunus americana | Prosopis nigra |