Bur Marigold.Bidens cernua.
Found through August and September in swampy grounds. It is very common, and grows from 1 to 5 feet in height.
The stalk is leafy and branching, large and tough-fibred, smooth, but grooved from the joints. The color is light yellow-green.
The long leaf is narrow, and tapering to a slender point; it is somewhat fulled upon the taut midrib, and the margin is irregularly notched, while the surface is smooth. The color is a strong yellow-green, lighter on the wide midrib. The leaves are opposite each other, and partly grown together about the stalk.
The small, tubular disc flower is dull tawny in color; the rays, usually 8 in number, are broad, and of a bright golden-yellow color. The large flower-heads are encircled by two rows of green, or greenish, bracts, the outer row being slightly twisted; they are somewhat nodding on short stems of equal length, and spring from the angles of the leaves.
The seed, armed with 4 stout prongs, and plentifully set with backward-pointing bristles, is familiarly known as “beggars’ tick” or “stick-tight,”—it never loses a chance to catch a ride on the clothes of the unwary passer-by. Its smooth grooved stem, swelling at the joint, is an interesting feature of this otherwise rather coarse plant.