Sclerotinia trifoliorum
Sclerotinia rot ( Sclerotinia trifoliorum ) is a type of fungus from the order of Helotiales. The species is a plant pathogen, it infects species of clover ( Trifolium ), but also other legumes ( Fabaceae ).
Description
The brown fruiting body ( apothecium ) arise singly a blackish sclerotia. They are stalked, more or less bowl-shaped and long. The fruit bodies have a diameter of approximately 8 millimeters. The ascospores are ellipsoidal, 12 to 18 microns in length and 6-10 microns in width. The mycelium is white.
Dissemination
The type is found at the base of the stem axis (but not at the roots ) of plants of the genus clover ( Trifolium ), but also other legumes ( Fabaceae ). It is distributed worldwide and is perceived in Europe, especially in snowy areas as winterkill.
Ecology
In late winter and early spring, the stem axis of the infested plants start to rot. The plants turn black and begin to die. They are covered with white mycelium, which is grouped to sclerotia and then turns black. The mycelium can also crawl over wet soil and thus infect other plants.