Saturday, December 22, 2012

Ferns as brooms

Species name: Psilotum nudum

Common name: whisk fern

Location: UWO Greenhouse

The whisk fern is in a genus of only two species, one of which is endangered throughout its native range. This species, the "naked" whisk fern, is native to southern Japan but now grows through much of the tropical and subtropical world. It is epiphytic, meaning that it can grow off of substrates other than bare earth, usually other plants (it can even grow on rocks and extract nutrients from the passing air currents and in rain water). It is even known to grow on unused power lines in some areas in Africa! When growing on other plants, it is rarely parasitic and instead just uses it as a prop.

Whisk ferns do get their common name from their most common use: as brooms. The branch-like appendages of the fern would be tied together (unlike most common ferns, the stems are actually quite tough and rigid) then attached to a long stick and used to sweep debris. Aside from the obvious use for this plant, there is at least one use that I was surprised to learn about employed by the Native Hawaiian people: as talcum powder. The spores were collected in bowls, and then used on the skin under loincloths to prevent chafing.

Because of the fact that these ferns are perennial species that are incredibly long-lived (even when you don't just compare them to other species of ferns), there has been much interest in the types of secondary compounds produced in the stems (which are actually modified leaves). There has been the suggestion that the whisk fern might be a goldmine of new antibacterial and antifungal chemicals that could be used in agriculture or medicine.