Looks like smartweed, Polygonum.

Vietnamese 'coriander' is a Persicaria odorata, so it is very closely related to Polygonum species and consequently similar in appearance. However, it is a tropical plant so I very much doubt it is what you have in your NY garden.

A few seasons ago, (I don't remember how many year's back) I bought Vietnamese Coriander from a local nursery. I don't remember it overwintering, but thought maybe I missed it and it came back again. The internet tells me that Polygonum is spicy and I didn't notice any taste, but to be honest, I only took a tiny bite of one leaf and chewed very briefly. Now that I know these are edible and don't have to fear for my health, I can have a proper taste. I'm away from the family garden for a week and a half and will taste some leaves when I get there and report the results.

I really don't think Persiacaria odorata could overwinter in your region unless there is something we don't know, like this is growing inside a greenhouse or something. It's a tropical plant.

It doesn't have any of the trademark spots on the leaves. And if you can't taste anything, then it's definitely not Vietnamese coriander. That stuff is potent.

That definitely looks like "rau răm" or vietnamese coriander to me.

I wasn't kidding about literally no flavor, so if it is Vietnamese coriander, it lost flavor after some ovewinterings.

ngan007 - It resembles Vietnamese Coriander because it is in the same plant family. But aside from the lack of flavour and lack of markings there is no way the tropical VC would survive a New York winter outdoors.

Hee hee - zone 11 -14 is what one website says for Vietnamese Coriander. Certainly not something that can survive a NY winter. I checked the NY Flora Atlas. One of these plants is most likely your tasteless plant:

Accepted Name Persicaria amphibia ssp. laevimarginata American water smartweed

Accepted Name Persicaria arifolia halberd-leaved tear-thumb

Accepted Name Persicaria capitata pink-headed smartweed

Accepted Name Persicaria careyi Carey's smartweed

Accepted Name Persicaria coccinea scarlet smartweed

Accepted Name Persicaria extremiorientalis far-eastern smartweed

Accepted Name Persicaria hydropiper water-pepper

Accepted Name Persicaria hydropiperoides mild water-pepper

Accepted Name Persicaria lapathifolia dock-leaved smartweed

Accepted Name Persicaria longiseta low smartweed

Accepted Name Persicaria maculosa lady's thumb

Accepted Name Persicaria nepalensis Nepalese smartweed

Accepted Name Persicaria orientalis prince's-feather

Accepted Name Persicaria pensylvanica Pennsylvania smartweed

Accepted Name Persicaria perfoliata mile-a-minute-weed

Accepted Name Persicaria punctata dotted smartweed

Accepted Name Persicaria sagittata arrow-leaved tear-thumb

Accepted Name Persicaria setacea bristly smartweed

Accepted Name Persicaria virginiana jumpseed

I have a tasteless plant that looks just like the Vietnamese Coriander growing wild in my garden in the Piedmont of North Carolina. I believe it to be "Lady's Thumb", many with striking dark red markings. Such a disappointment when I tried it and it had no flavor.

I don’t recommend nibbling plants you haven’t affirmatively and conclusively identified. People in my area end up in the hospital after mis-identifying poison hemlock as wild carrot or sweet cicily. Best to figure it out first.

Very disappointed because I find these in my garden, and they dont taste like anything