Looks like a Dianthus, maybe 'Fire Witch'.

WAG .. a dianthus ... ken

https://www.bluestoneperennials.com/DIFW.html

https://www.google.com/search?q=Fire+Witch%27+Dianthus&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjur8WQs7DQAhWL7IMKHdbqBZQQ_AUICCgB&biw=974&bih=744&dpr=0.9

i would have won.. if i didnt get lost looking at images.. lol ...

Dianthus blooms early in the season, then sometimes re-blooms later in summer depending on the variety. Look for flowering stems that were cut low.

Great, thanks for the ID, I just want enough so I can walk in it barefooted :)

It isn't a great candidate for walking on. It grows mounded rather than flat. It is rather prickly to the touch and it will not enjoy being crushed. Although the foliage is attractive, for most people the flowers are the main point. They grow several inches taller than the leaves and they will certainly be ruined by walking on it.

If you are looking for something soft to walk on I am rather partial to Thymus pseudolanuginosis - Wooly thyme. It lays flat, the flowers are tiny and the fragrance of the foliage is mild. It will take moderate foot traffic and if the area is large enough it is quite nice to lay on. A very tactile plant.

There is another possibility - and that is that we have misidentified it and it is actually Ameria maritima. You appear to have touched it and still thought it would be good to walk on. So possibly the leaves were not particularly stiff to feel? If we could just see a stem we could know for sure.

I'm not that much into herbaceous plants and this one struck me as different. The plant is in the Morris Arboretum in Philadelphia, not near me. However, I can check it out again next year.

Based on growth patterns, both in the large and small scale photos, it looks to me to be Dianthus rather than Armeria which IME is tuftier and doesn't spread as large or as densely as the groundcover Dianthus.

"Armeria which IME is tuftier and doesn't spread as large or as densely as the groundcover Dianthus."

I think that might depend more on location and site conditions. Here, armeria is often used as a groundcover so its ability to spread is rather significant. My first thought on seeing the photo was that the plant in question was armeria/thrift, as my experience with the low growing dianthus was that they tend to be a bit sparse in their spread and also patchy in their coverage.

Seeing the actual base of the plant with stems/roots could help as would any remaining signs of flowers. At this distance and detail resolution, both dianthus and armeria would look pretty darn similar.

Thanks for that GG48. I had no idea that both could be as variable.

Foliage looks like that of a pink.

Yes it does but bear in mind the common name for Armenia maritime is Sea Pink due to the similarity. I'm not sure anyone who had brushed their hand across dianthus foliage would consider it a comfortable plant to walk on barefoot. I just suggest keeping an open mind on it pending more information.

Not a thrift.

Well, that us told.

I am still not going to come down on one side or the other until we see stems.

Adamance aside, I would be interested to know what distinguishing characteristics shown in the photo would lead one to state definitively that this is dianthus rather than thrift. The appearance seems to indicate a much denser habit than one would normally see with dianthus and very much in keeping with this photo of armeria foliage (although the photo is showing with a frost rime)

As to suitability of either, both can be used somewhat interchangeably for a lawn substitute or spreading groundcover, although thrift is an easier care and longer lived plant overall.

I would still need to see root and stem structure or any flowers before I was convinced one way or the other!

Though this isn't a great photo, to my eye, his plant looks virtually identical in growth pattern and color to my Dianthus 'Greystone' though the foliage is a bit smaller. It has the same low, dense tufts of blue-gray foliage and relatively even edge from its outward expansion. I've had similar Dianthus plants with finer foliage but the same color and growth pattern. Here Armeria tends to grow in more distinct buns IME and the individual tufts of leaves are more distinct and a bit more green, though still in gray-green end of the scale. I've grown several types of both in at least two gardens and this is just my observations from what I see here in the NE.

That looks like Amsonia hubrichtii.

I think she's referring to the grey ground cover....

Yup, the grey ground cover to the left of the Amsonia and in front of the Thuja.

Leaf color, shape and arrangement is that of a Dianthus.

Well, now I have had a look on a different device with a better zoom facility. I can see a stem and it does indeed look like Dianthus. The OP clearly has tougher feet than I do. Wouldn't want to walk barefoot on pinks.

Looks like Dianthus to me.

Can Armeria have blue foliage? The blue in the example shown doesn't look like frost to me.

Different year, different location, I'm thinking same plant. One of the things that kept throwing me off about the first one was how closely cropped it was. Maybe there is a selection that naturally stays low and carpet-like? Pic taken this morning in Baltimore.

No, it is a lovely plant with the most wonderful scent.