Prim. Lin. Fl. Herbipol., 43. 1809.
Stems branched, rarely simple, to 30 cm; branches 1–5 pairs, from middle and distal cauline nodes; cauline internode length 0.5–2 times subtending leaves. Leaves: blade narrowly oblong to ovate-oblong, 2–9 (–12) mm, margins serrate, teeth 1–3 pairs, apices subacute to aristate. Inflorescences beginning at node (5–) 7–9 (–11); bracts green, sometimes purple adaxially, broader than leaves, oblong to ovate, length not more than 2 times width, 5–10 mm, surfaces glabrous or sparsely to densely hirsute and hairs eglandular, sometimes glandular-pubescent and hairs glandular, stalks 1-celled or 2-celled, 0.1–0.2 mm, teeth 4 or 5 pairs, longer than wide, apices acute, sometimes aristate. Flowers: corolla white, usually suffused with lilac, 8–10 mm, abaxial lip exceeding adaxial. Capsules narrowly oblong, 4.5–6 mm, apex truncate to retuse.
Introduced; N.B., N.S., Ont., P.E.I., Que., Ill., Maine, Mass., Mich., Minn., N.H., N.Y., Pa., R.I., Vt., Wis., Europe, Asia (w Siberia)
Varieties 7 (2 in the flora).
Occurrence of Euphrasia stricta in Alberta is based on the report by G. C. D. Griffiths (2002); no specimen has been located. Griffiths listed E. arctica subsp. borealis as new for Alberta, but both morphological and habitat descriptions fit E. stricta more closely. If true, then this introduced species has crossed the continent; all earlier records are from eastern Canada and New England (S. R. Downie and J. McNeill 1988).
"broader" is not a number.