Euphrasia officinalis

Stems 1-4 dm, simple or freely branched, floriferous in the upper 1/3 to 2/3; lvs ovate to suborbicular, 5-15(-20) mm, sharply 3-5-toothed on each margin, glabrous or sometimes hairy beneath; bracteal lvs similar, but the teeth more distinctly subulate or bristle-tipped; cal glabrous or nearly so, the lobes 2.5-3.5 mm at maturity; cor 5-10 mm, typically pale lavender with deeper purple guide-lines, the lower lip also marked with yellow, or seldom the cor deeper violet; upper cor-lip evidently bilobed; fr glabrous or nearly so; seeds 1.3-2 mm; 2n=22, 44. Dry or moist fields, roadsides, and waste places; native of Europe, early intr. into N. Engl., and now well established from Nf. and Que. to Mass., N.Y., and Pa., and inland to Ont. June-Oct. Divided by European botanists into a myriad of scarcely distinguishable microspecies, of which the following have also been attributed to our range: E. borealis, E. curia, E. micrantha, E. nemorosa, E. rigidula, E. stricta, E. tatarica, E. tetraquetra. The names E. americana and E. canadensis were based on intr. forms of this same complex.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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