In Jan 2014 almost the whole trunk of this dead tree growing next to the entrance gate to the Tabin Wildlife Reserve in east Sabah was covered with the fruits of a Tricosanthes cucumber. The cucumber liana plant itself appears to be dead.

The identification as T. sepilokensis is  a guess based on habit and habit. See  the text by de Wilde and  Duyfjes (2010)

According to de Wilde and Duyfjes (2010) some species of Tricosanthes cucumbers are monocarpic i.e. they produce  a massive crop of fruit in one big bang before dying.

A number of  Bornean plants especially the “suicide palms” Caryota, Corypha and Eugeissona are monocarpic. Monocarpic fruiting is believed to be an evolutionary strategy to defeat seed predators.

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Dispersal: The appearance of the abundant fruit on the bare trunk closely resembles that of a common forest liana fig Ficus punctata which fruits in a  a series of big bangs several times a year. We know from many observations that Ficus punctata is targeted  at gibbons for dispersal so the most likely reason for the abundant fruit display is to attract gibbons to eat the cucumber fruit and disperse the seeds.

Uneaten ripe fruits that fall to the ground will be eaten  and dispersed by a wide range of ground mammals including deer, rhinos, elephants and pigs. According to de Wilde and  Duyfjes (2010) when a trunk covered in T. sepilokensis fruit was felled by a storm at Maliau in Sabah the fallen fruit were eaten by Banteng (wild cattle).

Tricosanthes cucumber IMG_8672.JPG

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25 species of Tricocanthes cucumbers found in Borneo.jpg
According to de Wilde and Duyfjes (2010) there are 25 species of Tricosanthes cucumbers found in Borneo.
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de Wilde and Duyfjes (2010) Cucurbitaceae in Flora Malesiana Vol.19-2010