Rare Native Fern Rediscovered In Hawke’s Bay
20 October 2008
Rare Native Fern Rediscovered In Hawke’s Bay Area
Dr Leon Perrie, Te Papa’s Botany curator, and the Manawatu Botanical Society recently made an unexpected discovery of a maidenhair spleenwort fern population (Asplenium trichomanes s.l.) previously thought extinct.
The last identified specimens were recorded in the 1950s but their exact locality details were never recorded. The current population of ferns comprises just 9 plants in a single area of about 5 by 3 metres. The Department of Conservation (DoC) has been notified, but the exact locality is not being released more widely because of the plant’s scarcity. Dr Perrie said he was elated when the population was discovered during a field trip specifically to hunt for the fern.
‘I didn’t think our chances of finding it were very high, if at all, and was rapt when a team member called me over to positively identify it – I couldn’t stop smiling!’ said Dr Perrie.
Any additional finds of either of the species of the maidenhair spleenwort in the Hawke’s Bay would be very significant, and David Carlton of DoC (06 869 0494, email@example.com ) or Dr. Perrie (04 381 7261, firstname.lastname@example.org) would be grateful for notification. The species are most likely to found on limestone.
The maidenhair spleenworts differ from other similar ferns in having an unbranching, black, almost smooth stem, and in having its reproductive structures away from the margins on the underside of its leaves.
There are two species of maidenhair spleenwort ferns (Asplenium trichomanes s.l.) in New Zealand: “quadrivalens” and “hexavalens”. They look very similar, but have different numbers of chromosomes. The hexavalens species is common, but the quadrivalens species is very rare in New Zealand (it is common overseas); the only living plants known are the nine just discovered.
The taxonomy of the maidenhair spleenwort ferns requires further investigation which is why the two species do not yet have formal scientific names.