Ficus deltoidea normally grows as an epiphyte in the canopy of tall forest, but in this photo is growing in the ground on the summit of Bukit Patoi, Temburong, Brunei. Note that this plant has two entirely different shaped leaves with different venation, (1)0 Egg shaped and (2) Shaped like a spear blade. Note also the twin glands at the base of the leaf blade.
Ficus deltoidea IMG_3639.JPG
The rear of the leaf at the top of the plant shown in the photo above. This leaf has  two very clear black glands on the base of the leaf on the upper side and three glands on the leaf on the underside. Ficus deltoidea is so variable it is understandable that botanists described multiple different varieties.
A separate Ficus deltoidea  plant on the summit of  Bukit Patoi.  Note that there are no glands on the upper side of the  leaf but 3 glands on the underside of the leaf of the same plant  as shown in the photo below.
Ficus deltoidea. Typical view of the underside of the leaf blade showing 3 black glands. It is thought that these glands provide  food to attract ants which then defend the plant against leaf eating insects.
A third Ficus deltoidea  plant growing at ground level showing typical  oval leaves and fruit.
This variety  of Ficus deltoidea has both spear shaped and oval leaves growing on the summit of Bukit Patoi. Possibly this is a hybrid between plants with spear shaped and oval leaves.
A fourth Ficus deltoidea on the  Bukit Patoi summit with only spear shaped leaves.
Ficus deltoidea with spear shaped leaves on Bukit patoi summit.
Ficus deltoidea leaf showing different glands on the undersurface
The summit of Bukit Patoi must  have a climate  very similar to the forest canopy and several plants normally found growing in the canopy have become established.
View from the summit of Bukit Patoi, Temburong, Brunei Darussalam.

Bukit Patoi Map

Temburong, Brunei MAP