Monographs Details: Isanthus brachiatus (L.) Britton, Sterns & Poggenb.
Authority: Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Description:Species Description - Stems much branched, 2–4 dm, finely puberulent, glandular in the infl; lvs short-petioled, mostly elliptic to lanceolate, usually 3-nerved, acute; pedicels to 1 cm; cal-lobes 2–3 mm, in fr 3–5 mm; cor blue, the oblong lobes 1.5–2 mm; nutlets 2.5–3 mm, puberulent at the top. Dry soil; Vt. and Ont. to Minn. and Nebr., s. to Fla. and Ariz. Aug., Sept. (Trichostema b.)