NOTES ON ETHNO-BOTANY IN THE NEW TERRITORIES
125
Two native plants are accepted as sources of preservative dye. The first is the local dwarf mangrove, called locally hung ka tung (紅花冬). The bark and leaves are stripped, dried, and pulverized, and a reddish dye extracted. Cutch, too, can also be extracted from this mangrove plant and used in the tanning of leather. The second plant is a yam, pak shue leung (白薯莨; Dioscorea rhipogonoides). Dye is extracted from the underground tuber. This yam is cultivated under the same conditions as the common yam. The common yam, Dioscorea alata, is a minor crop. It is grown as an emergency food, as it presents little or no storage problem so long as the tubers are not dug up.
In the process of applying preservative dyes, fishing nets are treated with the white of duck eggs to which some tung oil is added. The nets are then steamed in vats before use. The yolk is salted, dried in the sun, and subsequently sold as ham tan wong (鹹蛋黃).
Many economically and medicinally useful plants double as hedge plants. Thick Pandanus growths border paths in many coastal villages and serve as barriers to keep cattle from wandering from path to field. Women and children nibble at the soft fleshy keys of the drupe which are then cast by the wayside. Village boys, too, pelt one another with the keys while playing. Perhaps these actions explain why Pandanus growths often line paths near coastal villages. Because of their toughness and pliability, Pandanus leaves can be plaited into many kinds of light durable articles and many partition walls of existing matshed huts are made of Pandanus leaves.
The prickly Opuntia and spiky Agave are also common wayside hedge plants. One species of Opuntia called locally sin yan cheung (仙人掌) meaning "the palm of the fairy-spirit" was at one time in the past grown for the benefit of cochineal insects (胭脂蟲) which throve on the succulent plant. According to the reports of many older villagers, in the days before the coming of cheaper and better chemical dyes, these insects were gathered from this Opuntia, roasted, and a red dye extracted from them.2 Agave, mentioned earlier, supplied the fibers for making twine and cordage.
Another common hedge plant is Jatropha curcas, called in Cantonese ma fung shue (麻楓樹) which means "leprosy shrub”.