Ode to a rare Mustard

Thelypodiopsis shinnersii (syn. Mostacillastrum vaseyi) is a rare annual mustard that's seemingly much more rare than previously thought, most likely due to the same old culprits of habitat destruction and invasive grasses. It was put on my radar by a friend who spotted it growing in Harlingen, Texas and couldn't figure out what it was. I don't know of many native Brassicas in the region either,…