SPIRAL FIG Ficus spiralis Corner (1960) SECTION:RHIZOCLADUS
Latin: Spiral fig – referring to the curious growth pattern of the vine as it spirals around the trunk of a host tree..
Plant: A locally common root climber around Kuching,but seemingly rare elsewhere. Unlike most root climbers which climb in a straight line up tree trunks F. spiralis grows in a spiral encircling the tree trunk. The spiral leaf bunches are separated by gaps where only dead brown stipules remain on the vine.
Leaf: Large 20-42 x 8-15cm. The leaves of young plants are smaller with fewer side veins. See the article on this site for a Ficus spiralis found at Mulu.
Fig: The figs are very small (under 0.5cm diameter), very hairy and ripen brown to yellow to white.
Similar species: None. The growth habit and leaf shape are distinctive
Distinguish: The growth form and appearance of this fig is totally unique.
Distribution: A rare fig which has been collected in lowland forest throughout Sarawak. The highest altitude recorded is 210m. The type was collected at Sematan, Kg Pueh not far from Kuching and according to Corner it is locally common at Bukit Kuap in the Kuching suburbs. Several collections are from secondary forest and it has been collected in disturbed flood plain forest at Mulu. In Kalimantan there are collections from Tembawang, Sanggau in West Kalimantan, Bukit Raya in Central Kalimantan and Ulu Kahayan in the hills of NE Kalimantan. Recently discovered in Sabah for the first time by Linus Gokusing.
Ficus spiralis of Sarawak. Corner (1975)
Indeed, F. spiralis is peculiar (figure 12); I do not know of any other fig with its intermittent manner of growth and its oblique direction. It is not uncommon in wet lowland forest around Kuching where I have studied it. Instead of ascending a trunk vertically, as usual in these root-climbers, it spiralizes obliquely round the trunk with a succession of leafy and leafless portions of stem. It has fairly large green and persistent stipules up to 30 mm long. The stem produces 5-20 nodes, generally 9, with leafy stipules but no stalk or lamina; then it produces 4-7 nodes with similar stipules and large lamina, to be followed by another ‘leafless’ stage, and so on. This alternation starts early in the seedling and no bathyphylls are formed.
The stem thickens little, up to 8 mm in diameter when the primary twigs are 5 mm. Short, freely hanging sprays develop from the creeping stem and, with the same interrupted leaf-arrangement and bear the small axillary figs 5-6 mm wide (dried).
The lamina (leaf) is the most fully developed of any Ficus species in SECTION RHIZOCLADUS; it measures 28-42 cm x 8-16 cm with 12-14 pairs of lateral veins, 7-13 intercostals, and no elongation of the basal veins. If the intermittent growth is peculiar, the rather stout twig, the many-veined lamina, the persistent stipules, and the lack of bathyphylls are primitive; perhaps, too, the oblique ascent..
I note here too, the strong resemblance in leaf between F. spiralis and F. rubromidotiis in the very different section of Sycidium (figure 12). Both species grow together in the forest round Kuching, the one as a root-climber ascending from the ground, the other as an epiphytic shrub rooting to the ground. A close ally of F. rubromidotis namely F. rubrocuspidata (figure 12), may grow with them but it is more often a riparian epiphyte. The small leaf of F. rubrocuspidata with simple venation is the leptocaul derivative from the more massive F. rubromidotis in the same way as Ficus sinuata ssp. cuspidata stands to ssp. sinuata. (Corner 1975)