Much like no. 1 [Amsonia tabernaemontana Walter]; lvs firm, shining above, narrowly lanceolate, to 15 mm wide, glabrous beneath; cal-lobes sparsely pilose, especially distally; cor-tube sparsely villous near the summit externally; follicles tending to be slightly constricted between the seeds. Moist sandy or gravelly soil; c. Mo. to Kans. and Tex. May.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
