a slight
ridge the entire length of both sides. Introduced from Europe, not yet a
prominent weed in Michigan.

[Illustration: Fig. 107.]

=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.

[Illustration: Fig. 108.]

=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.

[Illustration: Fig. 109.]

=Alfalfa. Lucerne.= _Medicago sativa_ L. Seeds varying much in shape and
size owing to their crowding in the pod when young, yellowish green to
light brown. The cuts give a good idea of the variety of shapes; surface
dull or somewhat glossy, often kidney shaped, with the scar in a
depression near the middle, the tips may be truncate or acute or
rounded, 2-2.5 mm. long in cross-section, oval; when viewed from one
edge it is seen to be bent or warped in various ways, half anatropous,
often seen with a slight depression extending along one edge from the
scar to one end, larger seeds more often flattened than are the shorter.
A prominent forage plant, the seeds of which are often adulterated.
Native of Europe.

[Illustration: Fig. 110.]

=White Sweet Clover.= _Melilotus alba Desv._ Flowers white; pods
straw-color to brown, coarsely and irregularly reticulate-ridged or
wrinkled; seeds smooth, dull, yellowish or greenish, more strictly
elliptical-oblong in outline than those of red clover and alfalfa,
bearing the broad, shallow notch near one extremity; 2-2.2 mm. long.
Introduced from