Previously Wen Qing introduced her study plant, Singapore Rhododendron (Melastoma malabathricum), at Black Dillenia. Now it’s my turn to feature mine, Simpoh Air (Dillenia suffruticosa) 
Pronounced Sim-poh Ay-eh (a direct translation from Malay to English would be Simpoh water [no idea what Simpoh means, but 'water' could be a reference to how their presence indicates a nearby, underground water source {1}]), this plant may be a ubiquitous shrub, but it’s also a very important pioneer species. To put it simply, pioneer species are the first plants that colonise wastelands, growing where there’s plenty of sunlight. They make the area more hospitable by providing shade for other plants. Through the process of succession, pioneer species will eventually be shaded out by taller plants. A lot of the time, land in Singapore is cleared for development, with small pockets in these areas left alone – that’s when the pioneer species are able to come in and start growing. If you drive/take a bus and look out the window, you’d be able to see that Simpoh Air grows in large numbers along the roadsides. It’s not unusual to find a wall of them. See how well they’re able to do, even in disturbed land where nutrients are poor and the soil has been heavily compacted by machinery?
Here’s a look at the leaves, flower, fruit and seeds of the plant:
Large, oval leaves of Simpoh Air.
The leaves of Simpoh Air have been (and still are) used as a food wrapper. In the past, it was used to wrap Chinese rojak (way better than disposable plastic containers, if you ask me, because leaves are biodegradable). Currently, it is still used to wrap tempeh, a fermented soya bean cake [2].
The area circled in red highlights the characteristic feature of Simpoh Air leaves. The leaf stalk clasps the stem, forming a wing. And because of this, it is also called the CB plant also has a rude Hokkien name, supposedly coined by army guys.
A single, large, yellow flower with a petal missing.
The above photo was taken rather late in the day, and if another shot had been snapped in the morning, the same flower would be looking way more radiant. Simpoh Air is one of the few plants that has a one-day flower, opening in the morning (apparently 3 am [1]), quickly gets itself pollinated by carpenter bees (Xylocopa spp.) (these bees do come as early as 6.45 am) ,and start to droop terribly by late afternoon. In fact, the petals drop off one by one (observed this for myself), until only the centre of the flower is left. This will then develop into a fruit, which is said to ripen in 36 days.
Update: the one-day flower characteristic is pervasive in the Dilleniaceae, but there are exceptions [3].
Happier-looking flowers.
For the casual observer, Simpoh Air may appear to have two flowers – yellow and pink. In reality, the pink structures are ripened fruits that have split open. In each of the multiple segments, bright red fleshy seeds can be found. And it is these that birds go gaga over, picking them out one by one and swallowing each whole. There can be as many as 30 seeds in one fruit (own observation).
Fruit of the Simpoh Air, taken at 5.30 am at Kent Ridge when the birds are still asleep.
By 9.00 am, the seeds (the red ones, anyway) were almost all gone. Anybody knows what the white ones are – ovules that did not get pollinated?
The frequency of seed removal does vary from place to place. Generally, by early afternoon, the seeds all have been taken, leaving the open structure bare (or containing the white ovules). After a day or two, the structure falls off near the parent plant…
Freshly ripened fruit still containing red seeds that was tossed onto the ground by a Plantain Squirrel (Callosciurus notatus). I saw the fruit fly out from one of the Simpoh Air patches I was observing.
…or even before the fruit has become limp (after a day), it may get plucked off by a foraging squirrel and tossed onto the ground carelessly.
Okay, so what’s so special about Dillenia suffruticosa?
Apparently, D. suffruticosa is the only plant known to have both one-day flowers and fruits. The fruits split open before dawn (the magic number being 3 am [1] again), and the seeds are rapidly taken by birds like Yellow-vented Bulbuls (Pycnonotus goiavier) and Pink-necked Green Pigeons (Treron vernans). However, where the plant grows also plays a role. For instance, ripened fruits found beside busy roads are avoided and seeds can be found late into the morning (and perhaps ignored totally). Apparently, the yield of fruits (total number in one patch) also matters (shall go on about this more in later posts). By late evening, the empty fruits start to droop, with the segments flattened backwards.
Picture of fruit taken slightly past 5 pm.
Typically, other plants flower and then fruit in consecutive steps, with each wave lasting for significant periods. Simpoh Air, however, has new flowers and fruits every single day, meaning that the food supply for birds are continually replenished. This essentially is the basis for the focus of my project, where I’m looking at the depletion rates of Simpoh Air seeds. How fast do the seeds get taken? How does this vary over time? What does this mean for the plant and for the birds?
Questions that yearn for answers!
References:
1. Tan, R. (2001). Simpoh Air. Retrieved January 23, 2010, from http://www.naturia.per.sg/buloh/plants/simpoh_air.htm
2. National Heritage Board. (2005). Singapore food prints. Retrieved January 23, 2010, from http://heritagefest.org.sg/2005/official/downloads/teacher_foodprints.pdf
3. Endress, P. K. (1996). Relationships between floral organization, architecture, and pollination mode in Dillenia (Dilleniaceae). Plant Systematics and Evolution, 206(1-4), 99-118.
