LILY FAMILY. LILACEAE.

[Illustration: Fig. 29.]

=Field Garlic. Wild Garlic.= _Allium vineale_ L. Seeds not seen,
apparently seldom produced; bulblets (b) light yellow or almost white,
obovoid to elliptical, 7-8 mm. long, when dry. Introduced from Europe.
Troublesome in pastures and tainting the flavor of butter; in wheat it
taints the flavor of flour. Persistent when introduced. The illustration
of grains of wheat (a) are given for comparison.

NETTLE FAMILY. URTICACEAE.

[Illustration: Fig. 30.]

=Slender Nettle.= _Urtica gracilis_ Ait. Achenes compressed,
lens-shaped, ovate, rarely oval, faces similar, smooth, dull and grayish
brown, .9-1.1 mm. long. Native of this country. Compared with U. dioica,
this achene is thinner and shorter. Prominent in low pastures.

BUCKWHEAT FAMILY. POLYGONACEAE.

[Illustration: Fig. 31.]

=Knot-Grass.= _Polygonum aviculare_ L. This door-yard weed is in no
sense a grass. Achenes unequally 3-sided, ovoid, acute, angles obtuse,
surface, dull, light to dark reddish brown, finely granular and striate
lengthwise. 1.8-2.2 mm. long, usually with the remains of calyx
attached. Native of this country. Common about door-yards.

[Illustration: Fig. 32.]

=Wild Buckwheat.= _Polygonum Convolvulus_ L. Achenes dull, jet-black,
equally 3-sided, elliptical to obovoid, minutely granular often with
faint longitudinal striation, the faces often more or less concave, the
angles rounded, 2.5-3.5 mm. long, sometimes with the remains of calyx
attached. Introduced from Europe. Often climbing up corn stalks.

[Illustration: Fig. 33.]

=Erect Knotweed.= _Polygonum erectum_ L. Achenes dull, light to dark
brown, unequally 3-sided, ovoid or rhombic, finely granular and striate
lengthwise, the faces sometimes concave, the angles rounded, 2.5-3 mm.
long, sometimes with the remains of calyx attached. Native to this
country. Of little account.

[Illustration: Fig. 34.]

=Smart-weed.= _Polygonum Hydropiper_ L. Achene dull, granular, light to
dark reddish brown, lenticular, acutely and narrowly or broadly
elliptical, or 3-sided, apex acute, concave on the sides, angles obtuse,
2-3 mm. long, sometimes with the remains of the dotted calyx attached.
Introduced from Europe. Wet land.

[Illustration: Fig. 35.]

=Dock-leaved or Pale Persicaria.= _Polygonum lapathifolium_ L. Achene
shining, dark to chestnut brown, 2-2.2 mm. long, flattened, circular to
broadly ovate with abruptly pointed apex, the bas