A native woodland mustard with tiny pale flowers, hairy stems and sharply toothed leaves that clasp the stem.
Toothed Rockcress field photograph. Select a photo to enlarge.
Family: Brassicaceae · mustard family
Genus: Boechera
Flowers: Tiny, white to cream, four-petaled
Leaves: Alternate, toothed, with clasping basal lobes
Fruit: Slender, elongated pods
Habitat: Moist woods, streambanks and bluff bases
Also known as Borodinia dentata and Arabis shortii.
Clasping, toothed leaves: The stem leaves have irregular sharp teeth and a pair of basal lobes that embrace the stem.
Hairy stems: Fine hairs continue up the flowering stem. Leaf margins and undersides are also hairy.
Small pale flowers: Four narrow white to cream petals barely project beyond the sepals. Flowers cluster at the tip, with developing pods below.
Slender fruits: The seedpods elongate as they mature and spread outward or angle upward.
Look in moist deciduous woods, along streambanks and at the bases of wooded bluffs. The small flowers appear in spring, generally April through June, and are easily overlooked among larger woodland wildflowers.
Native to the Midwest and parts of eastern North America. These field photographs were taken at Ryerson Woods, Illinois, in spring 2024.
Boechera laevigata
Smooth Rock Cress (Boechera laevigata) has a smoother upper stem and generally narrower upper leaves. Toothed Rockcress combines a hairy flowering stem with conspicuously toothed, clasping leaves.
Hairy Rockcress (Arabis pycnocarpa) also has hairy foliage and clasping leaves, but generally has longer petals and upright fruits. Compare mature pods as well as flowers and leaves.
The flowering cluster lengthens as the lower flowers develop into slender pods. Each flower has four petals arranged in the cross-shaped pattern typical of the mustard family. The mature pods split to release the seeds.
