1) 圆叶的是"野蒜",or"野韭菜". Don't be misled by Coubert. It's edible but tastes much worse.

2) It's not worthy the risk to "从国内带种子". You can order the seeds on-line. Here is just one of the many websites (I myself never tried on-line order though):

http://agrohaitai.com/indexchinese.htm

3) The best way is to ask your friends for "韭菜根" as Catfish recommended. If you do the seeding yourself, you may need wait at least one more year for something edible.