Corner’s drawings above show the very variable leaf shapes of Ficus aurata in Singapore and the southern half of the Malay Peninsular.
The narrow leaf variety has not yet been recorded in northern Borneo and in Borneo is only known from Kalimantan. In simple terms Ficus aurata in Kalimantan is closer in appearance to Ficus aurata in Singapore than it is to Ficus aurata in Sabah This the result of the continuous land connections between Kalimantan and Singapore in the past known as Sundaland.
GOLDEN HAIRY FIG Ficus aurata Miq. (1867) SECTION: ERIOSYCEA
Latin: Golden fig
Tree: A small tree with hairy twigs, leaves and figs to 15 m very common in secondary forest. Appears to be more tolerant of open and dryer conditions than F. fulva and is often seen along roadsides in open countryside.
Leaf: Very variable in size and shape, often palmate in young plants. The basal side veins run close to the leaf margin not straight at a fixed angle from the base as with Ficus fulva.
Fig: A medium size (1.5-2.2 cm) which ripens, green to orange to red. Barbets and bulbuls attack the ripe figs and swallow the small seeds surrounded by a thin pale aril. Male (gall) figs are significantly larger and paler than female figs and fall from the tree uneaten at which time they are coloured a pale yellow with a wide open ostiole.
Sex: Dioecious which means that trees are either female (which produce seeds) or male in which the figs act as brood chambers for fig wasps. Male figs ripen larger and paler than female figs. The Ficus aurata photo immediately, above shows ripe female figs.
(1) Ficus inaequipetiolata (narrow leaf) used to be considered a morph of Ficus aurata. Ficus inaequipetiolata is a Borneo endemic and it appears to be confined to northern Borneo.
Corner’s illustration at the top of this article shows that Ficus aurata also has a very distinctive narrow leaf form. This narrow leaf form appears to be common in the southern part of the Malay Peninsular and Singapore. In Borneo it has been recorded from Kalimantan but not yet from Brunei, Sabah or Sarawak.
(2) Ficus fulva which is less common in secondary forest on the edge of towns but more common along the edge of primary forest. The simplest and easiest way to tell the two species apart is by cutting open a fig fruit. The interior of F. aurata is full of sharp white hairs. With Ficus fulva, both male and female fig interiors are full of fleshy red tepals – (the fleshy bits surrounding the seeds) but no or few white hairs.
Ecology: The explanation for the difference is probably that Ficus aurata primarily evolved to be dispersed by large grazing mammals such as rhinos and elephants which eat the whole branch leaves and figs together whilst Ficus fulva evolved to be dispersed by birds, such as bulbuls that peck the fig open and bats that use their teeth to open the hairy skin.
The most likely reason the fig surface is exceptionally hairy in both F. aurata and F. fulva is to prevent the fruit being swallowed whole by green pigeons which predate the seeds.
Distribution: Common in secondary forest throughout Borneo up to 1,400 m, often in the same location as Ficus fulva, Ficus brunneoaurata and Ficus inaequipetiolata.
Range: Malaya, Sumatra, Palawan, Borneo.