Is 菜心 used in Mandarin? Is the vegetable 菜心 (Choy Sum - English rendering of Cantonese) called 菜心 in Mandarin? Is it pronounced "cài xīn" or is it pronounced as it would be in Cantonese?
When I spoke Mandarin in Guangzhou, I -- and the people I was talking to -- called it 菜心, càixīn. Outside of Guangzhou, I heard it called 广东菜心, Guàngdōng càixīn.