A large and complex Eurasian genus, the species often misidentified and with tendencies to hybridize. Thymus vulgaris L. is the common herb; it has ± tomentose leaves with revolute margins. Thymus serpyllum L. with stems pubescent on all sides is rarely cultivated in North America; most garden plants (as well as escapes) are other species, including the two below.
1. Stem ± terete, pubescent on the entire surface; leaves ± linear, with weak lateral veins.
1. Stem 4-angled, pubescent entirely or primarily on the angles; leaves elliptic to somewhat spatulate, with strong lateral veins beneath.
All species found in Thymus
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. August 24, 2019. https://www.michiganflora.net/genus.aspx?id=Thymus.