A plant anatomical space that is a slit in an anther lobe formed from when a dehiscence zone dehisces. [source: POC:curators]
Pollen may be released through the stomium. If you are annotating to this structure for Zea mays or other grasses, please also add an annotation to the corresponding floret type. Choose the most specific term possible from: spikelet floret (PO:0009082), tassel floret (PO:0006310), lower floret of pedicellate spikelet of tassel (PO:0006313), lower floret of sessile spikelet of tassel (PO:0006315), upper floret of pedicellate spikelet of tassel (PO:0006314), upper floret of sessile spikelet of tassel (PO:0006316).