Aquatic and Wetland Vascular Plants of the Northern Great Plains
41. Lamiaceae, the Mint Family
4. Prunella L. -- Selfheal1. Prunella vulgaris L.
Rather low perennial 0.5-4 dm tall from a small caudex or short rhizome; stems erect to decumbent, simple or branched, glabrous or sparingly villous below to more densely villous above, especially on the angles. Leaves principally cauline, smaller basal leaves commonly present; blades of cauline leaves lanceolate to ovate-lanceolate, mostly 3-5 cm long, 0.8-2.2 cm wide, bluntly acute to obtuse, entire to obscurely serrate; smaller basal leaf blades ovate, subcordate to rounded at the base; petioles mostly 1-3 cm long, villous. Flowers rather small, crowded in a short-cylindric bracteate spike 1.5-6 cm long, ca. 1.5 cm thick; bracts reniform with a cuspidate to caudate tip, mostly shorter than the subtended calyces, ciliate. Calyx green or purple, bilabiate, 7-10 mm long, pubescent mainly on lobe margins, the upper lip broad, shallowly 3-lobed, the lower lip slender, cleft into 2 narrow teeth, slightly shorter than the upper lip; corolla blue-violet, seldom pink or white, bilabiate, the tube about equaling the calyx, the upper lip hoodlike, arched over the stamens, extending 4-8 mm beyond the calyx, the lower lip shorter, with 2 small lateral lobes and a larger, erose middle lobe; stamens 4, barely exserted, the filaments bifid at the tip; style exserted. Nutlets flattened-obovoid, 1.5-2 mm long. Jul--Sep. Moist or wet places around springs, streams, seepage areas or fens; also in various drier habitats; uncommon in e and c ND, more common in s SD and NE, locally common in the Black Hills; (Nearly cosmopolitan).
Previous Section -- Physostegia virginiana (L.) Benth.
Return to Family -- Lamiaceae - The Mint Family
Next Section -- Scutellaria galericulata L. -- Marsh skullcap
