It may be a Vicia.

Yes! Thank you. I think you are right. On closer inspection, I can see remnants of dried up purple flowers, each on the tip of a tiny pea-pod. Vicia is a legume. If you look carefully, you can even see those pea pods in the picture (middle bottom). Now why didn't I notice these when they were in full bloom? Maybe next year.

Crownvetch, They improve the soil but some consider them invasive. They spread and are very weedy.

I vote for crown vetch. I can see the grabbing tendrils on the ends of the leaves in that photo. They do have small purple flowers. They are invasive and hard to get rid of and weedy. A pull will get you the tops but leave the root so they have to be dug out

Vicia = vetch

Crown vetch isn't in the genus Vicia, despite the common name. It's Securigera varia.

There are several kinds of crownvetch here in Central Texas.. I have been pulling it out in wads. They do NOT go into my compost heap.

Uh, OK, probably not a good legume to use as a cover crop then. I was envisioning soil nitrogenation.

Thanks for the correction floral.

Plant asked about isn't crown-vetch, original poster even mentioned the purple flowers (of a Vicia).

Well, I found little purple shreds that looked like they might have been flowers. Indeed, doesn't crown vetch have purple flowers?

The vetch that I have has TINY small flowers.

My mistake, I call it crown vetch but the common name is hairy vetch, or Vicia villas.

Hairy Vetch

Do you still have access to the plant? Some close ups would really help. The seed pods appear to be in pairs rather than racemes. Is that correct? If so it's unlikely to be Vicia villosa.

Definitely not crown vetch. I'm pretty sure that is Vicia sativa, which is one of the earliest Vicias to flower each spring. Those are known for their tendrils, and usually one-two flowers per inflorescence.

That was my feeling too, but I didn't know if it would be a candidate in that area. Hence the question about the paired pods.

I used an annual vetch I bought from the Natural Garden in Austin Texas, as a green manure in my small garden and it behaved well and I killed it before it seeded. They SAID it would not seed here in Texas. I did not take the chance and tuned it into the soil before it seeded..