My Bush Grape (Cayratia mollissima) plants have been growing on my fence more than ten years now. All this time they have been bearing bunches of attractive pinkish fruits that look like grapes. Dwarf Honey Bees and Common Honey Bees visit the flowers for the pollen and the honey https://besgroup.org/2019/01/16/bees-collecting-nectar-and-pollen-from-bush-grape-cayratia-mollissima-flowers/.
People who walk by are attracted to these fruits. Those who were curious may pop one into the mouth, to immediately yell loudly in pain. The presence of numerous tiny needle-like raphides found in the juice of the fruits cause intense pain.
Dieffenbachia, commonly known as dumb cane is another plant with raphides. Taro or yam needs to be boiled before eating to remove the raphides. Pineapples, tomatoes, kiwi fruits and spinach also have raphides but in lower content. Thus we do not feel the sting of the raphides when eating such fruits and vegetables. These raphides function as a defence against herbivores. Thanks to Muhammad Dzaki bin Safaruan who assisted me in obtaining images of the raphides from my Bush Grape fruits, I learn that these raphides come in various colours, namely blue, green and red.
Some months ago, I came across several Oriental Pied Hornbills (Anthrococeros albirostris) perching on my fence picking on the tips of the plants’ young tendrils to eat. On another occasion, one hornbill picked up a fruit and swallowed it. This is the first time I came across a bird, let alone any other animals except ants eating the fruit https://besgroup.org/2016/10/09/fruiting-of-bush-grape-cayratia-mollissima/.
I have not seen any animals eating the fruits, even when left in the open for a week when myna birds, squirrels, and Common Palm Civets (Paradoxurus hermaphroditus) were seen moving around https://besgroup.org/2016/10/09/fruiting-of-bush-grape-cayratia-mollissima/ Only ants go for the juice from ripe fruits.
