Okay, guess I found the answer. The site below says: "In Texas there are at least 39 species of Dalea, most of which grow in dry parts of the state" which makes it a little hard to know what you are getting when you buy it, but it seems I have both now :-)

Here is a link that might be useful: About Black dalea on Native Plant Society of Texas website ...

I used to see Black Daleas out near where I live...here and there. Now I hardly ever see any. Don't know if it was drought, colder winter temps or what, but they seem to be going away. Years ago I put a plant in my yard, but after a couple of years, it died. In that case, it probably got too much water.

Linda, thanks for passing along your experience. Same here with it dying. I also suspect too much water. I had a thick stand of the low growing one for three or four years in the "hell strip" and it disappeared after a wet winter. I went over to get some more from a neighbor's yard where I'd planted it and her's had died too..

The link above says it seems to be disappearing in many areas of the Texas Hill Country:

"Jan Wrede writes that black dalea has been removed from much of its former range by cattle browsing ("Trees, Shrubs, and Vines of the Texas Hill Country"). The severe overpopulation of deer probably will lead to its elimination in many areas of the Hill Country. Reportedly, black dalea survives where it grows within the protection of sticky agarita branches in parts of Kerr County. If you find black dalea in the wild, it is worth protecting."

It's a beautiful and very drought tolerant plant. I'll be careful to deeply amend the soil with decomposed granite when planting these in the back yard where the deer can't eat it. Any other suggestions to insure its survival?

I see some black dalea on the RT 12 from Dripping to Wimberley. THe deer keep it down to about 6 inches. I saw it because it was putting on a good bloom this fall. I planted some on a rough area of limestone rubble on a grade. It lhas staid alive unwatered through the drought (10 years) but the deer keep it at 3 inches. It comes back up from the ground. My cows used to hassle it too. It stays tiny.

It's supposed to like full sun and well-drained soil, and of course, should avoid overwatering. Said to tolerate sand, clay, caliche and limestone soil. I've got lots of the last two kinds of soil.