The edge of the sea is a harsh place, a borderland of elements at odds, a battle line where two worlds take turns to invade each other's spaces and impinge on slopes that must endure a daily change of guard between sallow straits and a stony island. At the eastern fringe of Pulau Ubin, on a promontory that straddles two channels and overlooks a flat of grassy beds, rain, wind and unmitigated earthworks sweep soil, wood, dirt and other terrestrial fragments towards rivulets that run to the shore, while the waves and rising tides send lines of jetsam and discarded resin to the high water mark, where they join heaps of Ulva and drift seeds in search of coastal settlements to form a layer of decay, of dead and dying things, that do little for lovers of long walks on clean beaches but offer a smorgasbord of flesh and fraying fibres for diners with greener habits – beachhoppers, ghost crabs, pigs out of sty, seaweed flies, monitor lizards, dog whelks, mynahs in raucous gangs.
The edges of Chek Jawa are too steep, too narrow, too hemmed in by the sea and a wall of trees to provide much of a beachhead for low, ground-hugging vegetation. But the sheared crowns of some of the outcrops that guard this cape provide, in parts that receive dunkings only from the most severe of storms, footholds for a herb that has lost its grip on mainland shores. On these plateaus of unpolished granite, foliage, petals, fruit and seeds from durians, nutmegs, sea almonds and fan-flowers drop, or float on seasonal breezes, into shallow basins and miniature faults – what remains after the monsoons have taken their toll is a sliver of humus, an ounce of sediment too thin even for unruly grains but enough to sustain populations of a wildflower that grows prostrate on stems bearing a spiral of fleshy leaves and tufts of axillary 'hair' resembling the hides of shrivelled hamsters and which must have struck Linnaeus, for he dubbed this plant the 'pilose purslane'. Their habit is ungainly and lacking in lushness, but Portulaca pilosa ssp. pilosa makes up for the sparsity with a constellation of delicate, rosy-pink blooms that light up the tips of its shoots and evoke, in the pale whorls that threaten to envelop the corolla and bracteole, Venus in furs, stars in a swaddling of vegetable fibres.
The hairy portulaca, which flourishes on ledges inhospitable to most other plants, owes its survival to photosynthetic pathways that allow it to thrive in water-stressed habitats. Evident on its leaves are a branching network of dark green lines indicating dense bundles of chloroplasts which receive carbon dioxide solutions in saturations that fuel growth in hot, dry conditions. Another mechanism may come into play during periods of drought, namely the ability to accumulate carbon dioxide after hours when the plant can stop holding its breath and open its pores to let in the sour stuff without losing too much fluid; come daylight, when the stomata are closed, dissolved gases stored in pockets to spare are shunted to the chloroplasts for conversion into sweeter bonds.
Local colonies of Portulaca pilosa – which may never have been common, for they escaped even Ridley's notice – appear restricted to rocky or sandy coasts: littoral deserts too dry for true halophiles, too bare for bushier flora but not nearly too wild for them fighting words don't come easy go hard or go home, truly. A different succulent, one formerly thought to be allied to Portulaca and named accordingly, still occurs in considerable densities on the upper end of exposed beaches, such as those of Pulau Semakau, Pulau Hantu and isolated stretches of Changi and Lim Chu Kang, where they emit a satisfying crunch underfoot en route to deeper parts. The herb probably suffers little permanent damage, for it is a diffuse, decumbent being that sprawls on stems secured to the ground by roots from regular nodes. The flowers, which share a base with the thickish but narrow leaves, are a far lighter, more delicate, shade of pink, but as the greenish tips suggest, consist of five coloured sepals rather than soft lobes, which frame a cluster of slightly darker stamens. Vast carpets may have tinged the lower reaches of the Geylang River in centuries past, for this waterway and the surrounding district are said to have been named after gelang pasir, a plant that is variously identified as Sesuvium portulacastrum or Portulaca oleracea. This botanical muddle matters not in times of callous appetites, for neither the provenance of a neighbourhood nor knowledge of natural histories that shaped recent landscapes can match, in debt and flavour, the pursuit of gastric availment through island geographies in nomen eet numen.