Is anyone here familiar with this rock garden plant? What other name might it be known by? I'd like to add it to our DB, but it doesn't appear to be an accepted name.

Yes, very familiar with it - an extremely hardy and long-blooming groundcover plant. It's name seemed somewhat mysterious many years ago but I thought it had been eventually come to be accepted, at least in cultivation.
I suspect part of the problem is a change in genus name... (can't remember off-hand the new genus name for most of what were Veronica.... assuming it hasn't changed again since then... ), but I wouldn't be surprised if the species itself is again in question.... as with so very many plants in this current vogue of "lumping" species. I haven't yet been able to post the majority of Veronica species I grow to this site. Guess I'll figure it out eventually.

Thanks, Lori.

I'd love to see if I can grow it. It sounds like a marvelous little plant.

Maybe you could add the plants you know as Veronica to the database under the name Veronica, and later change them to the new botanical name, with a cross-reference to the old name? It seems a shame to keep plants out of the database entirely until the botanists have made their minds up - which might take years, if they're doing DNA research.

That sounds like a good idea, June. Then just a note in the caption, maybe, stating that it's Whitley's Veronica.

Oh wow--
... new genus name for most of what were Veronica...
Really?

//as if it's not already hard enough for me to 'know' what something is...now it has to be something else?? and not even Lori knows??

I surrender:
insert little thing waving white flag

dirtdorphins said:Oh wow--
... new genus name for most of what were Veronica...
Really?

Well, after looking around some more, I take it back. Maybe it's not so grim as all that...
A few years ago, I got the impression from taxonomy sites that Pseudolysimachion was going to replace Veronica - at least for those species that don't have the characteristic "veronica"-shaped flower, but it looks like that has not been the case after all. USDA Plants uses Pseudolysimachion longifolium for Veronica longifolium (only) but other sites still seem to classify it as a Veronica. Sorry to cause unnecessary consternation. ;-)
So, I guess I probably just need to figure out (or wait for) IDs for my "unresolved" species.

~Whew~
Well then, for now, I will keep calling those potential Veronicas some kind of Veronica then.
I doubt that I can even reliably say Pseudolysimachion, at this point.

Here's what I have as Veronica whitleyi:

Some garden centers name it as Whitley's Speedwell.

Yes, good observation, Caroline, "speedwell" being the common name for Veronica.

And is this the same plant as veronica prostata?
Or is veronica prostata a different plant?

V. whitleyi used to be considered a different species but who knows now... the name seems to have drifted off the lists.
Edit: I should mention too that the leaf shape and plant form (especially the inflorescences) are very different from V. prostrata.

Thanks somewhere I have seeds for veronica prostata, but I have a clump of the whitlei one too.