From the US Forest Service Fact Sheet:
Scientific name: Sophora secundiflora
Pronunciation: sah-FOR-uh seck-un-dih-FLOR-uh
Common name(s): Texas-Mountain-Laurel, Mescalbean
USDA hardiness zones: 7B through 10A
Origin: native to North America
Uses: Bonsai; container or above-ground planter; hedge; large parking lot islands (> 200 square feet in size); wide tree lawns (>6 feet wide); medium-sized parking lot islands (100-200 square feet in size); medium-sized tree lawns (4-6 feet wide); recommended for buffer strips around parking lots or for median strip plantings in the highway; near a deck or patio; reclamation plant; screen; small parking lot islands (< 100 square feet in size); narrow tree lawns (3-4 feet wide); specimen; sidewalk cutout (tree pit); residential street tree; no proven urban tolerance.
Availability: somewhat available, may have to go out of the region to find the tree