Some Arboreal Myrmecophytes (Ant-house Plants) of the Solomon Islands.
Part One. Hydnophytum kajewskii of the Rubiaceae family.
Derrick J. Rowe.
Having recently returned from remote Bougainville Island situated in the very hot and humid northern reaches of the Solomon Islands archipelago, I can now share a little more information about a plant considered by world experts such as the taxonomist Dr Matthew Jebb to be one of "the most elaborate plants in the entire world". However, one must dissect a tuber and do a little study to understand all of the fascinating reasons for this assertion.
Hydnophytum kajewskii was found in enormously lesser numbers than the ubiquitous and highly variable form of another local tuberous species Myrmecodia tuberosa "salomonensis" but it was not difficult to locate. Indeed, on our very first drive up into the rugged Crown Prince Range above Arawa, Bosco (as he prefers to be called) my guide actually found a truly fascinating mature plant attached to a semi rotten branch that had fallen from the tree above.
Most specimens were found growing under rainforest canopy, yet one particularly large specimen was located in a site extremely exposed to the vagaries of weather right on the crest of the Panguna road where it then descends down to the mine site on the other side. Indeed, this specimen was so large that at first I thought it might be another species but a strenuous climb to get much closer showed that it too had diagnostic rows of large lipped entrance holes on its upper edges. All specimens were found at altitudes of around 1,000 meters, therefore my plans to visit Panguna Mine a focal point of the recent civil war proved to be essential in this regard.
Some specimens were observed to contain ant colonies (probably a Philidris sp observed.) but larger infaunal assemblages such as cockroaches, centipedes and millipedes have been recorded as well as quantities of rainwater. Certainly a number of ant-house plant species appear to be evolving toward the accommodations of animals other than ants. However, the original symbiosis was almost certainly instigated by the constant presence of the enormous numbers of ant species found throughout tropical arboreal habitats. But no plants were dissected; this was purely a photographic assignment.
My visit has helped to increase the local's awareness of the wider world's fascination for plants that to them are perhaps boringly mundane but they are now very aware of their local ant-house species. I have suggested to Steven Tamiung my guide and now expert ant-house plant spotter that he should exporting seed which will surely interest botanical gardens and research institutions worldwide. Steven can be contacted through his boss Tour Operator, Zohn Bosco Miriona ( pictured above with H. kajewskii ), email <firstname.lastname@example.org>. New ventures such as this will surely help to improve their quality of life.