I painted Penicillium stained with trypan blue. Penicillium fungi are important post-harvest pathogens, for example citrus green mould is caused by Penicillium digitatum.

The painting depicts the structure of a Penicillium conidiophore, resembling a simplified blue tree with rows of circular spores at the tips of its branches. It includes the stipe (trunk), rami (branches), metulae (sub-branches), phialides, and conidia (spores).