The little 5-parted flowers, white, or rose colored, grow in small close heads, on the ends of smooth foot-stems, from the angles of the upper leaves. The leaves are pretty in shape and color, though so far apart as to make small impression on the passer-by; the lopping stalk supports itself on the surrounding vegetation by means of its backward pointing prickles; it turns a russet-red in autumn. A shining, brown, 3-angled seed is developed within the long-lasting flower. [Illustration: TEAR-THUMB: Polygonum sagittatum.] *Knotweed.* _Polygonum Pennsylvanicum._ Found in barrens and waste places in August and September. Branching much and sprawling in manner, this plant grows from 1 to 3 feet in height; it is jointed, noticeably shining, and smooth except for the new growths and flower-stems which are rough with hairs. Its color is green, somewhat red at the joints, which are covered loosely by sheaths of a coarse weak fabric. The leaf is long-pointed at each end, and roughened by hairs on the ribs, edges, and upper surface; the texture is flimsy, and the color a crude green. The arrangement is alternate. The small and inconspicuous flowers are 5-parted, and vary from pink to green-white in color; they are tightly and irregularly bunched in a terminal club-shaped spike, with a little leaf at its base--frequently a second bunch of flowers occurs a little lower down the stem. Found commonly in great masses the plant serves to hide the ugly remnants man casts into the fields it chooses for its habitation. [Illustration: KNOTWEED: P. Pennsylvanicum.] *----* _Polygonum amphibium._ Found in swamps in September and October. The single stem, 3 or 4 inches high, bears a few leaves, and is large, round, hollow, and juicy; a dull-reddish-green color, that is dark near the foot. The leaf (varying from 2 to 5 inches in length) is oblong with a pointed tip and wedge- or heart-shaped base, an entire margin, and prominent midrib; it has a thin, leathery texture, and a very smooth shining surface; in color it is dark green, much toned with dull red, the midrib lighter. The leaves, on short stout stems, clasp the stalk with a dry, red-brown sheath enfolding the joint; they are placed alternately. The flowers are 5-parted, the tips of the divisions seldom spreading, of a bright rose-pink, coarse hue. They are gathered in a close club, set on a short, terminal, green stem. The lower of the three or four leaves float upon the surface of the water or lie on the mud of this plant’s miry home. [Illustration: ---- P. amphibium.] BIRTHWORT FAMILY. ARISTOLOCHIACEÆ. *Wild Ginger.* _Asarum Canadense._ Found in rich soil in woodlands, blossoming during May.