=Silvery Cinquefoil.= _Potentilla argentea_ L. Flowers yellow, achenes dull white to brown, unsymmetrically ovoid or short kidney-shaped, slightly flattened, 0.5-0.7 mm. long, smooth or marked by a few longitudinal curved ridges, some of them forked. Introduced into Michigan from Europe or possibly from the eastern states. Thrives in sandy land.
=One kind of Cinquefoil or Five-finger.= _Potentilla Canadensis_ L. Achene unsymmetrically ovoid, light straw-color to brown, ridges indistinct, short, wavy, branched and broken up, (these ridges are different from those of P. argentea or P. monspeliensis) 1 mm. long, the achene is less flattened and narrower in proportion. Native from Me. to Ga. Miss.
=Rough Cinquefoil.= _Potentilla Monspeliensis_ L. Flowers yellow; achenes nearly white to light brown, unsymmetrically ovoid, or short kidney-shaped, slightly flattened, 1 mm. or less in length, clearly marked by a few longitudinal curved ridges, the longer ones forked. Indigenous to Michigan, thriving on moist or wet land.
=Ax Seed. Ax Wort.= _Coronilla scoparioides_ Koch. Seed reddish brown, oblong, slightly flattened and curved, 4-5 mm. long, 1.5 mm. wide, with a circular scar in a depression on the middle of one edge, and a slight ridge the entire length of both sides. Introduced from Europe, not yet a prominent weed in Michigan.
=Bird's-foot Trefoil. Ground Honeysuckle. Bloom-fell.= _Lotus corniculatus_ L. Seed light brown occasionally mottled with black, shining, spherical to ovoid, slightly compressed near one edge, 1-1.2 mm. in diameter, the compressed portion (raphe) extending half to three-fourths the length of the seed to the hilum or scar, above this the seed is narrower. Introduced from Europe. Seldom met with in this country.
=Black Medick. Nonesuch.= _Medicago lupulina_ L. Flowers light yellow; pods black, oval, much flattened, spirally coiled, causing the two extremities to nearly meet; 2-2.8 mm. long; seeds smooth, dull yellow to green, oval, flattened, kidney-shaped, with a tubercle near the middle of the concave edge or like the figure, 1.5-1.8 mm. long. Introduced from Europe and becoming frequent in grass land. Its worst feature is to supply seeds that may be mistaken for and mixed with seeds of alfalfa and red clover. The seeds differ from those of alfalfa in being more commonly egg-shaped than kidney-shaped in outline. The scar is nearer the small extremity in these seeds than in those of alfalfa. For pasture this is less valuable than white clover.