Cardamine, a Wonderful Winter Groundcover

In the midst of winter, when many herbaceous plants have gone dormant, there is one that remains to enliven the muted colors of the forest floor (or garden) with its emerald green foliage. Cardamine diphylla (previous name Dentaria diphylla) is known by the common names toothwort or crinkleroot, and is a member of the Brassicaceae, the mustard family. 

📸 Andrew Lane Gibson

The foliage of this woodland treasure appears in mid-to-late fall, remains as a lovely groundcover throughout the winter, and then, in spring, stalks of small, white-flushed-with-pink, bell-shaped emerge; the entire plant seldom reaches over 3-4 inches tall. Upon the onset of hot weather, the entire plant goes dormant. Leaves of toothwort closely resemble those of Pachysandra procumbens, Allegheny spurge (our native pachysandra), and people often confuse the two. Toothwort grows best in shade or part-sun in moist rich soil, which encourages it to slowly extend its rich green carpet. Because it goes dormant in the summer, this plant is surprisingly drought tolerant once established. 

The rhizomes of this plant form a matted tangle just under the soil surface and have a knobby, tooth-like appearance. The genus name Dentaria refers to teeth, alluding to those protuberances on the roots; the specific epithet (second word in a botanical name) “diphylla” means two leaves, and refers to the pair of opposite leaves on the bloom stalk. We can discern much about a plant by deciphering its botanical name. 

Though there are other species of Cardamine found in our part of the country, this is the one most often encountered. Its native distribution is the eastern U.S. and Canada - and it’s been documented growing in 32 Tennessee counties. At Reflection Riding, this species may be found in several locations. Be sure to visit us to see this emerald beauty!