Three-fourths of the rarest plants are found in Hawai`i, California, Florida, Texas, and Puerto-Rico, and the U.S Virgin Islands.

Mount Weialeale in Kauai, Hawai`i.

East Bay near San Francisco, California.

In Florida, scrub habitat at Frostproof.

In Texas, Hill County within Edwards Plateau.

In Puerto Rico, Guanica, coastline.