Since it has been 25 days since I posted this on Quora, and all that happened was it was marked as needing editing (and perhaps also as needing to be in English), I chose to cross-post here.
The question text on Quora
On Chinese Wikipedia, “夜来香” is mapped to some 5 different plants (see source). Which of those four is Teresa Teng's song referring to?
The source comment
Wikipedia link: 夜来香 (歌曲) - 维基百科，自由的百科全书
Options therein given for Yelaixiang:
- Cestrum nocturnum (aka night-blooming jasmine, the one I suspect the song is referring to);
- 葉香木 (what is that?) ;
- Polianthes tuberosa;
- Telosma cordata;
- Oenothera biennis.
So what plant is this Yèláixiāng? Is it the night-blooming jasmine (cestrum nocturnum), as I suspect, or one of the other 4? And what is 葉香木?
The Japanese version of the song calls the Yelaixiang:
夜来香白い花 | Yeraishan shiroi hana | Yelaixiang white flower
Of the above, number 4 is a yellow flower, and so is number 5. Baidu gives the following image for number 2:
So number 2 isn't even a flower. That leaves us with number 1 (Cestrum nocturnum aka night-blooming jasmine) and number 3 (Polianthes tuberosa).