Ask Mr. Smarty Plants

The only species of the genus orbexilum found in our Native Plant Database is Orbexilum pedunculatum (Sampson's snakeroot). It is a member of the Fabaceae (pea) family, and we saw it referred to in another source as "mountain pea," although most of the sources call it "Sampson's snakeroot." 

From a website called Sagebud, we extracted the following information about this plant:

"Orbexilum Pedunculatum, or more commonly known as Sampson’s Snakeroot, is a forb/herb (a forb/herb is a non-woody plant that is not a grass) of the genus Orbexilum. It’s duration is perennial which means it will grow year after year. Orbexilum Pedunculatum or Sampson’s Snakeroot‘s floral region is North America US Lower 48, specifically in the states of Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Missouri, Mississippi, North Carolina, Ohio, Oklahoma, South Carolina, Tennessee, Texas and Virginia."

According to our page on this plant Orbexilum pedunculatum (Sampson's snakeroot), this plant is commercially available. So, we tried our usual go-to mail order seed supplier for natives of this area, Native American Seed. No luck. Next, we went to our National Supplier's Directory and put Hempstead TX into the "Enter Search Location" box, which gave us a number of native seed companies and nurseries in your general area. All have information and contacts; if the specific businesses you get in touch with do not have the seeds for this plant, they may be able to give you information on how to find it. Apparently, this plant is native to East Texas, it is probably growing in your fields somewhere in Waller County. We would also suggest you contact the Texas A&M AgriLIFE Extension Office for Waller County.  They may know a locale where it is growing and you could gather seeds. 

Images of Orbexilum pedunculatum (Sampson's snakeroot) from Google