Shopping for Hoa Thien Ly (Fragrant Cynanthe flower)

We were just in Vietnam and could not get enough of an edible flower called either Da Lai Huong or Hoa Thien Ly (Fragrant Cynanthe flower). I would love to find this in Chicago and attempt to recreate some of our favorite dishes. A Vietnamese coworker was confident I would be able to purchase around Argyle or in Chinatown. Unfortunately I've been to multiple markets around Argyle as well as in Chinatown and I've not had any luck.

I understand it is seasonal to summer and my time is limited...can anyone help?

I am far from an expert, but I go to the Argyle markets several times a year and have never seen this.

If it's seasonal to summer, you might still be a little early (think of the timing of corn & tomatoes).