Blanket Fern (Asplenium subglandulosum)

Blanket Fern (Asplenium subglandulosum), a tough indigenous ground fern found throughout Australia and New Zealand as an inhabitant of rock crevices, and a very atypical occurrence in this Bourke Street drainage pit.

Formerly treated as two species in a separate genus, Pleurosorus rutifolius and P. subglandulosus, this fern is now classified as a single species in Asplenium, although unfortunately the digitised records remain scattered hither and yon across that old taxonomy. It is absolutely an adorable and valuable indigenous fern, and as with other indigenous urban ‘weeds’ its presentation here should do nothing to diminish the regard we hold for this plant in its often remote and inaccessible natural settings. And how lucky are we to be able to see this fern set a foothold in the urban karst like a future champion!

Long-time readers will know that this channel has a nested obsession with ferns on urban structure. As an even more niche scavenger hunt, several species of fern do establish on drainage infrastructure within Melbourne and its suburbs wherever the variabilities of light, moisture, chemistry and windswept spores line up for them.

The ‘weedy’ occurrence seen here was established on a thick moss layer at the seam between the kerbstone and the lower wall of the drain pit, and must have been receiving dependable seepage from the substrate surrounding. Perfect conditions for a shy little rock fern in the midst of the big city!