Paranephelium xestophyllum  is one of two Paranephelium species that occur in Borneo. Paranephilum are in the Rambutan family (Sapindaceae)  and  these two species are very similar in appearance to the Horsechestnuts (Aeschalus) of Europe and N. Asia, also in the Sapindaceae. As with Aeschalus there is no aril (edible pulp) attached to the seed, therefore dispersal by primates is extremely unlikely.

Paranephelium IMG_1222.JPG

The Horsechestnuts (Aeschalus) are dispersed in two ways. Large browsers e.g. elephants, deer, pluck the fruits hanging from small trees when they are ripe to swallow the pericarp and defecate the seed.  If the shiny seeds fall  directly to the ground they are collected and scatter-hoarded or larder-hoarded by rodents e.g. rats or squirrels.

Paranephelium IMG_0216.JPG

Paranephelium IMG_0214.JPG

Paranephelium IMG_0220.JPG
The distinctive leaf venation indicates that this is Paranephelium xestophyllum which is locally common in the forest at Sepilok. The individual  tree in this article was photographed in the Rainforest Discovery Garden.

Paranephelium IMG_0221.JPG

Paranephelium IMG_0210.JPG
Tony Lamb photographing Paranephelium xestophyllum in the Rainforest Discovery Garden at Sepilok in Sabah.

Red Langur Borneo resized.jpg

According to Glyn Davies who studied Red Langur feeding ecology at Sepilok Red Langurs (Presbytis rubicunda), the diet consisted largely of young leaves and unripe  fruit and seeds especially seeds without any sweet pulp (aril) surrounding the seed. Thus Red Langurs were seed predators of Paranephilium seeds.

Davies (1991) Seed eating by Maroon Langurs

For further information on the two Paranephelium species in Borneo see;

Davids (1984) Taxonomic revision of Paranepheliulm (Sapindaceae) BLUM1984029002008