1. Woody shrub (mostly dying back nearly to the ground in Michigan); corolla 4-lobed; stamens 4; flowers purple.
1. Herbs; corolla 5-lobed; stamens 5 (4 plus a staminodium (sterile filament) lying under the upper corolla lobe in Scrophularia, with brown to greenish flowers); flowers white, yellow, greenish, or brownish, rarely pink.
2. Cauline leaves all or mostly opposite on fertile stems; corolla brownish, clearly bilaterally symmetrical and ± 2-lipped.
2. Cauline leaves all or mostly alternate on fertile stems (lowermost leaves sometimes opposite and rosette of larger basal leaves sometimes present); corolla yellow, white, or pinkish, nearly regular.
All species found in Scrophulariaceae
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. July 22, 2017. http://michiganflora.net/family.aspx?id=SCROPHULARIACEAE.