FICUS FORSTENII Miq. (1867) Scarce strangler
Latin: Honors the two famous botanists Johann Reinhold Forster and his son George who collected plants on Cook’s second Pacific expedition 1772-75.
Habit: Medium size strangler (to 25m) confined to primary forest in the lowlands with a patchy distribution, indicating that this fig species may have originated either in Sulawesi or the Philippines and entered Borneo from the east across Wallace’s Line.
Sex: Dioecious.
Leaves: Large oblong leaves 12-20 cm long by 5-12 cm wide with a long petiole up to 5.5 cm. Normally 12-(20–26) pairs of side veins.
Fig: Large oblong figs 2-2.5cm diameter and up to 4 cm long. Figs ripen bright orange to red to purple. The figs are enclosed by calyptrate bud covers when young.
Similar species: The large conspicuously veined leaves invite confusion with the leaves of F. drupacea and F. annulata. Both the side veins and the tertiary veins on the upper leaf are sunken resulting in the upper surface of the leaf having a bullate or corrugated appearance. Note that with the leaves of F. annulata only the side veins are sunken NOT the tertiary veins.
Leaf comparison F. annulata and F. forstenii
Both F. forstenii and F. drupacea leaves may sometimes have a scurfy (wooly hairs) appearance.
Distinguish:
(1) F. annulata figs ripen green not red and the fig fruit often have a peduncle or stalk. F. annualta is usually a thick liana rather than a large strangler.
(2) F. drupacea leaves normally have (6-) 8-12 (14) pairs of side veins and the upper surface is even/smooth above without sunken side veins.
Distribution: Widespread on the east coast of Sabah west to Ranau and Poring and the Maliau Basin but apparently absent from West Sabah. Most common in the lowland forests of E. Sabah, with only a few records from elsewhere.
Sabah: Sepilok, Poring, Danum- on the summit of the limestone hill at BRL and opposite the front entrance to the Borneo Rainforest Lodge. Also Lahad Datu, Tawau. At Maliau, the second most common strangler after Ficus kerkhovenii.
Brunei: No records.
Sarawak: There are two collections in the Leiden Herbarium from limestone hills near Kuching (Kg Bidi, Bau) hinting at a relict distribution most likely deriving from a dryer more seasonal climate in the past when this fig would have been much more widespread.
Kalimantan: Samboja near Balikpapan in E. Kalimantan.
Range: Widespread and common in the Philippines and Sulawesi. Rare in Malaya and patchy in Borneo. Never recorded from Singapore or Sumatra.
- Ficus forstenii collected in primary forest at Merotai Besar near Tawau.
