ght vertical grooves on each side, incumbent. This may soon
appear in Michigan.

[Illustration: Fig. 94.]

=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.

[Illustration: Fig. 95.]

=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.

When mature, large plants become tumble weeds. Apparently native to this
country.

[Illustration: Fig. 96.]

=Ball Mustard.= _Neslia paniculata_ (L.) Desv. Small fruits, greenish to
light yellowish-brown, globular, 2 mm. in diameter, covered with
net-veined ridges; 1-2 seeded, cotyledons incumbent. Not yet known in
Michigan but may arrive any time. Native of Europe.

[Illustration: Fig. 97.]

=Tall or Tumbling Mustard.= _Sisymbrium altissimum_ L. Flowers
cream-color; pods long and narrow; seeds reddish yellow, oblong, about
1.5 mm. long, the apex winged. Mucilaginous when wet. Cotyledons
incumbent. Introduced from Europe. One of the worst weeds in the
northwest.

[Illustration: Fig. 98.]

=Hedge Mustard.= _Sisymbrium officinale_ (L.) Scop. Flowers yellow,
seeds reddish brown or yellow, oblong, while lying on the flat side,
circular in outline at the middle as viewed from the edge, straight on
one side from the middle tapering to each end. 1-1.5 mm. long.
Mucilaginous when wet. Cotyledons incumbent. Introduced from Europe.

[Illustration: Fig. 99.]

=Penny Cress.= _Thlaspi arvense_ L. Flowers white; pods thin, double
convex, nearly circular; seeds deep reddish brown, flat-oval or ovate,
covered on each side by 12-14 curved ridges which originate and
terminate at the narrow extremity. 1.5-2 mm. long. Cotyledons accumbent.
When eaten by cows the milk and meat has a disagreeable taste. A bad
weed, especially in the north-west. Introduced from Europe.

ORPINE FAMILY. CRASSULACEAE.

[Illustration: Fig. 100.]

=Mossy Stonecrop.= _Sedum acre_ L. Seed light, reddish-yellow, somewhat
glossy, obovate to oblong, pointed at the base, slightly anatropous,
co