Timonius singularis (Rubiaceae)

Timonius singularis
Epiphytic habit.

Imagine a Gardenia masquerading as a fig and you’ll get a mental picture of what Timonius singularis represents. This rainforest plant is found at mid altitudes to upland areas and is known as the False Fig. The epiphytic habit of this species attests to the behavioural plasticity of the great Coffee family (Rubiaceae). Anyone who has walked around with some botanical awareness would undoubtedly have experienced the manifold manifestations of Rubiaceae and come to associate its members with a dazzling variety of trees, shrubs, vine and herbs. Now here we have an epiphyte, and whats more, one that seems to behave like a strangling fig. It develops roots on a host tree and then sends it down towards the ground. I haven’t seen it strangling anything though. Apparently, it is also known to grow on rocks, just like some figs. An evolutionist would say ‘convergence’, but looking at this from a storyteller’s point of view, one could imagine that the figs let this tree in on some of it’s ‘trade’ secrets!

While it is called a False Fig, the differences between it and figs are obvious. Timonius singularis has opposite leaves and a lack of sap when stems are broken. In appearance it actually resembles the Freshwater Mangrove (Carallia brachiata) quite closely because of the leathery leaves of which veins are hard to discern on the undersurface. However, the epiphytic habit, occurrence of ‘craters’ near the midrib called domatia, lack of dark dots on the leaf undersurface, and larger stipules instantly distinguishes it from Carallia. The flowers and fruits are reminiscent of the much more commoner Tim tim (Timonius timon) which is a proper tree.

Another good feature which will distinguish this species from any other is the numerous (and somewhat faint) tertiary veins like streaks that run parallel to each other and also to the secondary veins. This feature is best seen holding a leaf up against the light.

The False Fig is a little known botanical curiosity of Far North Queensland, Cape York and New Guinea and certainly one that deserves looking out for.

Timonius singularis
Large stipules that fall off, unlike many other Rubiaceae which retain an interpetiolar stipule.

Timonius singularis
Pairs of opposite leaves arranged at 90 degrees to each other (i.e. a decussate arrangement)

Timonius singularis
Domatia on the leaf underside are typically longitudinal slits, like little chasms situated near the midrib. These domatia don’t always turn up very well in all specimens

Timonius singularis
The impression made by domatia can be seen on the upper leaf surface

Timonius singularis
Venation detail. Note the fine tertiary veins that run very close and parallel to each other and also with the secondary veins.

About David Tng

I am David Tng, a hedonistic botanizer who pursues plants with a fervour. I chase the opportunity to delve into various aspects of the study of plants. I have spent untold hours staring at mosses and allied plants, taking picture of pollen, culturing orchids in clean cabinets, counting tree rings, monitoring plant flowering times, etc. I am currently engrossed in the study of plant ecology (a grand excuse to see 'anything I can). Sometimes I think of myself as a shadow taxonomist, a sentimental ecologist, and a spiritual environmentalist - but at the very root of it all, a "plant whisperer"!
This entry was posted in Habitat - Rain forest, Lifeform - Epiphytes, Rubiaceae (Coffee family) and tagged , , . Bookmark the permalink.

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