Microbotryum tragopogonis pratensis

During the lunchtime excursion on 22 May about plant parasites, a remarkable species took centre stage: Microbotryum tragopogonis-pratensis. Not long before, this rare species had been discovered for the first time on campus by Jaap Oosterom.

This unusual parasitic fungus has a preference for Tragopogon pratensis, a plant that typically displays cheerful yellow flowers. But when the fungus strikes, things take a different turn.

The fungus hijacks the plant’s flowering structure and replaces the yellow petals, styles and stamens with a dark brown, powdery mass – a cloud of fungal spores. Instead of attracting bees for pollination, the plant now spreads the fungus. Infected flowers are no longer capable of producing seeds.

The excursion offered a surprising glimpse into the hidden world of plants and their unwelcome passengers. In addition to smut fungi, the group also encountered rust fungi, aphids, galls and mildew. So be sure to keep your eyes open when you spot a plant on campus with a striking or unusual appearance – you might just discover a rare plant parasite!