Mahonias are shrubs with woody stems. This is instead a fern that looks like holly fern (Cyrtomium).

The leaves of holly fern sort of look like this, but there are no sori on the underside of these leaves. The underside of the leaves are dull green. The tops are shiny green. I guess that's not clear from the pictures. Quite un-fern like.

Embothrium is right. It is 100% a fern and is actually completely fern like. It is also 100% not Mahonia which is a large flowering shrub.

If you have a lot of it, and you don’t know where it came from, chances are it is this one: https://www.texasinvasives.org/plant_database/detail.php?symbol=CYFA2

Well after looking more closely, there ARE sori, but on just a few fronds. Most leaves on mine have absolutely none. I read now about "fertile fronds", which have them and "sterile fronds" that don't. Japanese holly ferns have them. It seems that fertile fronds are deciduous, and somewhat larger, and sterile fronds are evergreen and a bit smaller. I see fronds coming and going, but I never realized that the ones that go were actually horticulturally distinct. OK, thanks, I think the question is now answered, and I know more about ferns!

I find it odd that these are considered invasive. The ones I have in the ground have been in their bed for decades, with no expansion.

Dan, just as an aside, since your plant definitely is a Cyrtomium sp., but there IS a low growing mahonia: M. repens. It can't be mistaken for a fern, as it has definitely woody stems, and blooms its head off in Spring, but it does have a ferny effect, mine staying under 18" tall. It's the most graceful of all mahonias, and makes a great ground cover, in my opinion. It should be much more used than it is. It's hard as the dickens to come by, though. I'm also not sure how it would do in TX, but its natural range is from British Columbia to NM.

That's interesting. Thanks. A low-growing mahonia is attractive to me, and maybe I'll look around for it. It seems to be highly drought, shade, and heat tolerant, which are good. Looks to be commonly available online.

You’re right, Fig. I was thinking of those Mahonias with much longer pinnate leaves which more resemble the Cyrtomium.

Certain Asian mahonias and their single North American relative Mahonia nervosa (probably not a likely plant for Texas) produce a lot more fernlike effect than M. repens.

'Soft Caress' Mahonia (southernlivingplants.com)

The nice thing for me about both Mahonia and Cyrtomium is that they are highly shade tolerant, My bed gets less than an hour of direct sun. Not sure why Mahonia nervosa would not be OK for Texas, although where I am in Texas, we have alkaline calcareous soil, and some sources say they don't like that much.