6171 Descurainia shade of rocks and boulders as 6170 6172 Arabis Fendleri (Wats.) Brevne [4] petals pinkish, pedicels widely spreading, siliques pendulous, as fff 6170 6173 Lesq. aggusum Torsini' (Bry) Wats. pedicels sigmoid, flo. yellow, styles persistent, annual Tomillo Flats near Tomillo Creek, 56 miles south of Marathon, Big Bend National Park, Brewster Co., April 17 [6175 not used] 6174 Thelypodium texanum (Cory) Rollins petals white, anthers exerted, purplish filaments white, pedicels horizontal, siliques nearly horizontal. [red ?] Upper Tomillo Creek, Big Bend National Park, about 60 miles south of Marathon, Brewster Co. April 17