Commelina erecta L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Perennial from a cluster of thickened fibrous roots; stems erect or ascending, to 1 m, usually branched; principal lvs linear to lanceolate, 4–15 × 0.5–4 cm, the sheaths white-ciliate, somewhat prolonged at the summit into rounded, often flaring auricles; spathes arising near the summit of the culm, solitary or in small clusters, short-peduncled, broadly semi-deltoid, often with conspicuous radiating cross-veins, the margins connate in the lower third, upper pet 10–25 mm, the lower one much smaller and white; 2n=56–120. Dry, usually sandy soil; s. N.Y. to Pa., O., Mich., se. Minn., Io., and Wyo., s. to S. Amer.; also Old World. Highly variable, but only with difficulty divisible into vars. Var. erecta (C. virginica, misapplied; C. elegans), with lanceolate or lance-ovate lvs 10–15 ×1.5–4 cm, and with the spathes glabrous or nearly so, is mainly Ozarkian (with us), but extends ±throughout the range of the sp. Var. angustifolia (Mich.) Fernald (incl. C. crispa), with linear lvs 4–10cm and small spathes 1–2 cm, centers in Tex., but extends irregularly into our range. Var. deamiana Fernald, with linear lvs 10–15 cm, the spathes 2.5–3.5 cm and often pilose at base, occurs mainly on sand dunes from Ind. and s. Mich. to Neb., occasionally s. and w. to Tex. and Ariz.