I saw this cool map recently, shared on the Lady Bird Johnson Wildflower Center’s Facebook page from the Biota of North America’s Facebook page.
Verbiage from that Facebook page explains the map as follows:
The map is based on distribution of woody plant species that occur in this region but not in the other identified "hot spots". Most occur together in central Texas. Even more occur across the Rio Grande in Coahuila. The Balconian "hot spot" is located at the southern end because that is where the biota survived the last and previous glaciations. Leaf through the other maps in this series and you will see similar treatments for our other regional woody floras. An illustrative species is *Berberis (Mahonia) swaseyi* of Travis, Hays, Comal, Kerr, Bandera and Real Counties in Texas. A species with very similar morphology was described from 38 million-year-old Florissant (National Monument, Colorado) volcanic ash lake beds where it was part of the "Madro-tertiary Flora". There are many more species of animals (mostly invertebrate) with this distribution because they are adapted to life on and among these woody plants. The Barton Springs Salamander and the listed endangered cave arthropods are part of this set of relict communities.
I had to read this about six times, but as I understand it, this map illustrates the distribution of woody plant species that occur in this region (Great Plains/Prairie region), with the highest concentration occurring in Central Texas. (The other maps the passage refers to are on Biota of North America's Facebook page.)
You wouldn’t know it from my property, which is overrun with Ashe juniper and live oaks. But these seem to be really smart people, so I believe them!
I like maps; I hope you do, too.
My favorite spot today is out in a wild area. My daughter and I were mining for rocks last week when we both noticed and admired this grouping of twist-leaf yucca (Yucca rupicola), prairie fleabane (Erigeron modestus) and prairie verbena (Glandularia bipinnatifida).