MUCH of the western and southern parts of Peninsular Malaysia have suffered extensive land development in recent decades, resulting in the loss of what was once a rich patchwork of lowland rainforests and wetlands, including freshwater and peat swamps.
What remains are small fragments of jungle designated as forest reserves and undeveloped land comprising secondary forest or belukar that lie between vast rubber and oil palm plantations. Many rivers and streams, especially those that flow through inhabited areas, are highly degraded due to the dumping of human and industrial waste without regard for local environmental laws.
Despite this extensive loss of the region's original vegetation, it is still possible to find isolated spots where the original vegetation and fauna cling to existence, even at the very edges of frantic human activity.
Cryptocorynes are a genus of aquatic plants belonging to the aroid family (Araceae) which also counts as members several household potted favourites such as the money plant (Epipremnum aureum), dumbcanes (Dieffenbachia spp.), taro yam (Colocasia esculentum), peace lily (Spathyphyllum wallisi) and Anthurium 'lilies' whose brightly coloured inflorescences are a must for every floral cascade.
For fanciers of Cryptocorynes, Johor is a state of desire. But first, a little biogeographical history. The genus Cryptocoryne ranges from India and southern China all the way to New Guinea, but its epicentre lies in the heart of Sundaland, the now-sunken landmass that once covered what is now the South China Sea, the Javan Sea and the Straits of Malacca.
As recently as 12,000 years ago, the Ice Age trapped much of the world's freshwaters in high latitude glaciers, making it possible for plants and animals in Sundaland to spread across this shallow shelf. Great rivers once connected what is now the eastern part of Sumatra and western parts of Kalimantan and though they are now gone, these regions continue to betray their past land links in the sharing of species that could not have spread across the seas otherwise. Thus, closely-related bettas (e.g. the wine bettas) are found in suitable habitats from Sumatra to Peninsular Malaysia and Borneo, while Cryptocoryne species such as C. griffithi, the C. cordata complex and C. longicauda are found in both Peninsular Malaysia and Borneo.
No wonder then that Johor, with its former location as the deep interior of Sundaland, harbours a wealth of Cryptocoryne species, to be at least 6 of the known 13 Peninsular Malayan species. These are: C. ciliata, C. griffithi, C. longicauda, C. nurii, C. purpurea, C. schulzei. C. 'purpurea nothovar. purpurea, a species now believed to be a natural hybrid was described from specimens found near Kota Tinggi. Most of the state's remaining Cryptocoryne habitats are to be found in the interior, eastern and southeastern parts, as much of the state's western coast and south are heavily populated and have succumbed to extensive industrial and urban development.
Cryptocorynes are sensitive plants that thrive only in the shelter of lowland rainforest habitats offering good shade, high humidity and iron-rich but generally nutrient-poor clay substrates. The streams in which they grow may be permanent or seasonal, in which case the plants will develop an emergent form to survive the dry periods. Flowering takes place in both emergent and submerged conditions. As long as the inflorescence (this terms refers to what appears to be the 'flower' of the plant but which is really a structure that houses the small individual flowers) has its opening above water, the plant can be pollinated as insects are able to descend the watertight tube to reach the male and female flowering parts (stamens and pistils) in the kettle at the bottom, which can frequently lie deep in the water or even buried in mud. The distinctive shape and colour of the (usually-long) limb at the top of the inflorescence tube is vital to identifying many Cryptocoryne species as the plants' foliage is highly variable in shape, size and colour.
Human activity such as logging and clearing of habitats are not surprisingly usually detrimental to Cryptocorynes. Water pollution brings a tide of chemicals and fluctuating nutrient levels that disrupt the plants' growth, while physical pollution results in sedimentation that cause water turbidity. The lack of vegetation around the stream exposes the habitat to extreme heat and aridity and also probably means the loss of pollinating insects.
Despite all this damage, Cryptocorynes can still grow in degraded habitats if favourable conditions re-emerge and populations upstream survive well enough to naturally restock the lower reaches. Mature oil palm estates, for instance, have large trees that offer ample shade for streams that flow through the plantations. During one of our regular expeditions to Johor, Green Chapter found one such estate near the town of Kota Tinggi where a remnant population of Cryptocorynes was recently discovered.
