sporangium

These pollen gene controllers are active in maidenhair’s sporangia, the tissue where spores develop.

Then something magical happens: The fungus stops eating and rearranges itself into a giant stalk with a ball of cells — a sporangium — on top.

The gold was gone; now bunches of grapelike sporangia glittered.

"It's rare to get this many sporangia with well-preserved spores that you can measure," Leslie added.

The blackberry-like clusters set in the reproductive tiara are sporangia containing many spores, each with a ridged annulus like the bristles on a Roman helmet.