Scutellaria ovata (Heart-leaved Skullcap)
|Also known as:||Ovate-leaved Skullcap|
|Habitat:||part shade, shade; average moisture to dry; rich hardwood forest, floodplain forest, shaded bluffs, rocky slopes|
|Bloom season:||July - August|
|Plant height:||12 to 28 inches|
|Wetland Indicator Status:||GP: FACU MW: FACU NCNE: FACU|
|MN county distribution (click map to enlarge):|
|National distribution (click map to enlarge):|
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Spike-like raceme up to 12 inches long at the top of the stem, with smaller auxiliary racemes arising from upper leaf axils. Flowers are blue-violet to purple, 3/8 to 1 inch long, tubular, the 3 upper lobes fold together forming a rounded hood over the mouth of the tube. The lower lip is broad, 3-lobed, violet to white speckled with darker purple. The calyx holding the flower is green and about 1/8 inch long. At the base of the short flower stalk is a small, leaf-like bract. The stalk, bract and calyx are all covered in spreading, glandular hairs.
Leaves and stems:
Leaves are 1 to 4 inches long, up to 3 inches wide, opposite, heart-shaped with a pointed tip, toothed with rounded or bluntly pointed teeth, veiny, hairless to sparsely hairy on the upper surface with soft short hairs on the underside, on a hairy stalk up to 2 inches long. Stems are erect, stout, square, branched in the upper plant and densely covered in glandular and/or non-glandular hairs. Plants may form colonies from horizontal stems (stolons and rhizomes).
Heart-leaved Skullcap is a rare species in Minnesota, limited to the Mississippi River valley and its tributaries in our southeast counties, where it reaches the northern fringe of its range. According to the DNR, it was originally listed as a Special Concern species in 1984 and elevated to Threatened in 1996 after biological surveys conducted in the 1990s found only 7 populations. It is at risk primarily from destruction of its forest habitat due to agriculture, grazing, logging, road construction, and disruption of the natural river water level cycles. It is currently listed Special Concern in Wisconsin. While USDA currently lists 9(!) subspecies of S. ovata, these are not universally recognized and the distinguishing characteristics are not well documented, though some of the factors seem to be whether hairs are glandular, density of hairs, whether the floral bracts are longer than the calyx, whether bracts are stalked or toothed, and largest leaf size. The species found in Minnesota is subsp. ovata (also known as var. versicolor), which is glandular hairy, has floral bracts that are usually stakless and toothless and consistently shorter than the calyx.
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Photos courtesy Christopher David Benda taken in Illinois.
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