Publication: Harvard Pap. Bot. 11: 64. 2006.
selected vouchers: WTU
Notes: FNA7: "Boechera atrorubens is often treated as a variety of B. sparsiflora (e.g., R. C. Rollins 1993), it is readily separated from that species by having proximal stems sparsely (versus densely) pubescent with much smaller (0.15 versus 1.5 mm) trichomes. The two taxa rarely grow in proximity and, in areas where they are sympatric, B. atrorubens is further distinguished by its narrower (1.5-2 versus 2-5 mm) petals that are dark reddish purple to indigo (versus lavender or white)."