According to Berg (2005) the following figs that grow in Borneo have “calyptrate bud covers” covering the young fig fruits: F. benjamina , F. binnendijkii, F. cucurbitina, F. consociata, F. elastica, F. forstenii, F. globosa, F. lawesii, F. subcordata, F. stricta.
But what is a “calyptrate bud cover” ? According to Corner’s (1978) diagram (below) a calyptrate bud cover is a pair of thin covers like a stipule that entirely surround the young fig fruit (A stipule surrounds the young leaf bud in figs). Underneath the calyptrate bud covers the young Ficus elastica fig also has a pair of thin bracts. The bud covers tend to be brown and hairy.
According to Zhang (2014) the purpose of Calyptrate bud covers may be to protect the young fig from parasitic fig wasps or to regulate the entrance time of pollinating fig wasps.