=Hare's Ear.= _Conringia orientalis_ (L.) Dumort. Seeds brown, surface checked off into minute irregular pits or patches; broad oval, 2-2.5 mm. long, in section nearly circular, except two opposite slight grooves near one side. Cotyledons incumbent. Introduced, not common.
=Sand Rocket.= _Diplotaxis muralis_ (L.) DC. Flowers yellow, seeds reddish yellow or reddish brown, broad oval, somewhat flattened. Mucilaginous when wet. Introduced from Europe. A vigorous weed.
=Worm-seed or Treacle Mustard.= _Erysimum cheiranthoides_ L. Flowers yellow; seeds reddish yellow, smooth, dull, about 1.2 mm. long, ovoid or oval, more or less flattened, varying much in shape; some of them acute, rhombic or triangular, becoming mucilaginous when wet. Probably introduced from Europe. If not already in some portions of the state, we may at any time expect to find three other species of Erysimum. A vigorous and prominent weed.
=Apetalous Pepper-Grass.= _Lepidium apetalum_ Willd. Petals usually wanting, sometimes 2 and minute; pods flat, nearly circular; seeds reddish yellow, flattened, ovate, 1.5-1.8 mm. long, or more exactly, nearly straight on one side and roundish on the other. Mucilaginous when wet. Cotyledons incumbent. When well developed in open places it becomes a tumble weed. Apparently naturalized from Europe.
=Field Pepper-Grass or Cow Cress.= _Lepidium campestre_ (L.) R. Br. Petals white; pods flat, nearly circular; seeds dull, dark brown, obovoid, with base acute, more or less flattened on three sides, 2-2.5 mm. long. Mucilaginous when wet. Cotyledons incumbent. Naturalized from Europe.
=Hoary Cress.= _Lepidium Draba_ L. Seed reddish brown, surface slightly uneven, slightly flattened, oval to broad oval, 2-2.3 mm. long, usually with two slight vertical grooves on each side, incumbent. This may soon appear in Michigan.
=Golden Pepper-grass.= _Lepidium sativum_ L. Seed reddish yellow to reddish brown, oval, slightly compressed, often nearly straight on one edge, usually showing two vertical grooves on each side, 2.5 mm. long, cotyledons incumbent. This is not a grass but a plant of the mustard family; it has escaped from cultivation.
=Wild Pepper-Grass.= _Lepidium Virginicum_ L. Petals white, pods flat, nearly circular; seeds granular, dull, reddish yellow, flat, ovoid with one edge straight, the other rounded, usually with a slight wing on the broad end and on the round edge. 1.5-1.8 mm. long. Mucilaginous when wet. Cotyledons accumbent.