Thursday, 16 April 2015

The mystery of the Amanite of Bweyeye!

Cercopithecus l'hoesti
Today, we have a meeting in Bweyeye, a village on the edge of the Nyungwe National Park (970 km²), located in the south west of Rwanda on the border with Burundi, not far from the Lake Kivu.  The mountain forest of Nyungwe is perhaps one of the best preserved in Central Africa.  It has an exceptionally rich fauna and flora: around 13 species of primates, 32 species of amphibians and 38 species of reptiles and not to forget a thousand species of plants.  The mushroom flora is not so well known, just like in the surrounding countries and regions.  This is the motivation for our scientific mission which has as a goal of gaining a better knowledge of edible mushrooms.

Rendez-vous in Batwa-land

After two hours hiking through a maze of paths in the montane forest of Nyungwe, we arrive in Bweyeye.  Here the local population are hunter- gatherers.  Jean Marie, a forest ranger we met from an earlier scientific mission in October of last year, is waiting for us.
The first exploratory mission in October already indicated the presence of strange Amanites – from the group ‘phalloides’ or ‘marmorata’.  This remains to be confirmed but it has almost certainly been introduced with Eucalyptus trees originating from Australia.  This is not so exceptional.  Many mushrooms have been spread across the entire world in the way.  The hyphae or mycelium of the fungus were hidden on the roots of the Eucalyptus or Fir trees.  But most surprising is that this Amanite is considered as edible by the local population.  To science species of this group are unanimously considered as deadly poisonous !

Is the Amanite edible?

Jean-Marie found a local inhabitant that would act as a guide in our search for the Amanite.  The aim: to collect large quantities of Amanite to carry out genetic and toxicological analyses.  In this way we can determine the species and check the presence or not of deadly poisons.  In the meantime, Assoumpta, remained in the village to find out how local people prepared these mushrooms for eating.

Without some effort you will not reach your goal said Jérôme Degreef, the scientific coordinator of the expedition.  Ahead of us a steep climb to the top of the hill where these famous mushrooms can be found.  We are looking for mushrooms with a volva, which is a sort of sack that remains on the base of the stem (stipe), a characteristic morphological feature of Amanites.  After three hours of trekking we find some perfect specimens of other mushrooms – but no Amanites.  They nevertheless grow in large numbers in October.  A look of despair could be seen on Jérôme’s face until finally our local guide leads us to a plot of ground where he believes we could find what we were looking for.  ‘Yes that’s it’ shouted Jérôme, and as quick as lightning the mushrooms were photographed, listed and harvested for our collection.

After some ten minutes we find another three examples in various stages of growth (see photo).  
Sadly, the amount of material is far too limited to be able to carry out a toxicological investigation.  
We take the opportunity to ask our guide if he eats these mushrooms and how he prepares them.  His answer is yes, but he removes the cuticle of the cap before cooking them.  This confirms what Assoumpta was told by the village women.

Tomorrow we will return to continue our harvest but to be sure of success we ask our guide and the local village children to help.  What will the result be? That will see on Friday.

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