The photographs above and below show the Pinang Palm or Betel Nut Areca catechu growing wild on small islands in the delta of the lower Kinabatangan River on the coast of East Sabah. Photos taken May 2024.
Areca catechu has been cultivated for thousands of years over a very large area of South and East Asia east to New Guinea and islands in the western Pacific.
However the centre of distribution of the genus Areca (c. 47 spp.) appears to be the islands of South East Asia with the highest diversity on the island of Borneo with 22 spp. of which 20 are endemic to Borneo.
Clearly cultivation and escapes from cultivation which have become naturalised have played a large part in the current distribution of A. catechu.
Like the coconut Cocos nucifera cultivation by humans is probably the most important dispersal agent.
Similar to the coconut the internal hard nut is covered with a fibrous flotation or buoyancy husk.
As the fruit has no external flesh to attract animal dispersers, this indicates that the founder population of A. catechu was originally dispersed by rivers and sea currents from one river mouth to another around the coasts of S E Asia.
Is the Kinabatangan floodplain population proof of an original wild population, or the the result of river dispersal of rain washed fallen fruits from the upriver villages?
It would certainly be interesting to find out.
