SUBTERRANEAN FIG Ficus subterranea Corner (1960) SECTION: SYCOCARPUS

Latin: Under the earth – referring to the location of the figs.

Local names: Kelabit: buah abung. Iban: entimau.

Habit: Small forest tree to 5m. Has been found as a roadside shrub.

Sex: Dioecious.

Leaves: Oblong leaves 7-26 cm long by 2.5-8 cm wide. Almost symmetric.  Berg notes that on herbarium collections there are “persistent subulate buds” in the leaf axils up to 8mm long. i.e. sharply pointed buds which do not fall off in herbarium collections. See photo below.

Fig: Medium sized reddish slightly hairy earth fig with several to many large soft lateral bracts on the side of the fig. The figs grow on long stolon like roots at ground level like the other 8 species of earth figs in Borneo.

Similar species: Eight species of earth figs have been recorded in Borneo 4 of which could possibly be confused with F. subterranea. We list the differences below.

Distinguish

  • Ficus beccarii also has symmetric (even) narrow leaves figs but the leaves have a very long extended drip tip. The figs have hard hook like bracts not soft triangular flap bracts.
  • Ficus stolonifera. The figs are soft without obvious bracts and ripen bright red spotted white.
  • Ficus geocharis. The leaves are similar but the base of the leaf has an ear or auricle on one side. The figs have hard not soft bracts.
  • Ficus malayana. Has broad slightly asymmetric leaves whilst the fig has hard strongly hooked bracts.
  • The 3 species of the Uncinata complex figs (the most common earth figs in Borneo) all have highly asymmetric (unbalanced) leaf shapes with large lobes at the base of the leaf. The upper sides to their leaves are hairy and the leaf edges are serrated (dentate

Distribution:  Endemic to N. Borneo. A rare fig in herbarium collections. Leiden Herbarium (NATURALIS)  has only 4 collections, 3 of them collected in 1961 by the Royal Society Expedition to Eastern Kinabalu and one collection from Sungai Belalong in Brunei by Corner in 1959.

An uncommon fig in Sabah where we have only found it growing next to the roadside in the Crocker Range at c. 1,000m asl.

IMG_7510.JPG
Ficus subterranea. Note the soft triangular bracts on the side of the fig fruit and the small pointed bud in the leaf axil near the small fig on the right.

L.1617341l Kinabalu RS 1961 - ENHANCED.jpg