Growing on moist limestone soil next to the creek
Found these at base of mountain, behind some large boulders.
"Sap can be used as insecticide or repellent, hence the common name" ~ Michael Eason
I was fortunate to see this species twice in one week in SE Texas. I got these distant images of a soaring Swallow-tailed Kite at Village Creek SP with my Canon point-and-hope camera.
eBird checklist: https://ebird.org/tx/checklist/S135932382