Euphrasia officinalis (Tartary Eyebright)
|Also known as:||European Eyebright|
|Habitat:||part shade, sun; disturbed rocky or gravelly soil; inland forest roads, ATV trails, utility rights of way|
|Bloom season:||June - August|
|Plant height:||3 to 14 inches|
|Wetland Indicator Status:||none|
|MN county distribution (click map to enlarge):|
|National distribution (click map to enlarge):|
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The small, irregular flowers are ¼ to 1/3 inch long with a 3-lobed lower petal and a 2-lobed or notched petal above. Color is pale bluish white to deeper lavender, with prominent darker veins on the hood and lower lobes, and a bright yellow spot on the lower lip. Flower cluster opens progressively in a short spike at the tip of stems and branches, each flower attended by a leaf-like bract. Both the calyx and bracts are mostly hairless.
Leaves and stems:
Leaves are opposite, egg shaped to nearly round, 1/5 to 2/3 inch long, with 3 to 5 sharply pointed teeth on each side, stalkless. Both surfaces are hairless except for a few scattered hairs along veins on the underside. Stems are branched or unbranched, covered with short hairs throughout. Both stems and leaves are typically dark green, sometimes with a reddish tinge.
The Eyebrights make up a complex of circumboreal species, described into hundreds of subspecies of which only a few are readily distinguishable. Euphrasia officinalis (which may be a synonym for Euprhasia stricta, Drug Eyebright), is recognized to represent a number of purported European introductions into the New World. Within recent years it has spread rapidly throughout the Arrowhead region along forest roads and recreation trails - spread by the human penchant for motorized travel. It puts at risk Minnesota's native Hudson Bay Eyebright (Euprasia hudsoniana) by encroaching upon its narrow habitat niche along Lake Superior's north shore, and by its potential for hybridization that would snuff out our native's unique evolutionary genotype. The two species look essentially identical to the casual observer, however E. hudsoniana has hairy leaves where E. officinalis are mostly hairless. Also any populations observed away from Lake Superior's rocky coastline are certain to be the foreign species. Finally, what's in a name? Euphrasia as a whole is not well defined or described, and according to the DNR, the genus is under review at Flora of North America. What is currently recognized as E. officinalis in Minnesota may well get a name change in the future, as this name seems to be out of favor with most references.
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Photos by K. Chayka and Peter M. Dziuk taken along an ATV trail in Superior National Forest, and at Silver Bay's public boat ramp in Lake County.
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