Polygonum glabrum Willd. (smooth knotweed)

Family polygonaceae

An annual herb, the Polygonum glabrum Willd. (smooth knotweed) likes to inhabit the humid wilderness. It has erect or obliquely upward stems with a tint of red. With many branches and enlarged internodes, the smooth knotweed has needle-shaped leaves with a length from 10 to 20 centimeters. The entire apex is acuminate. Tomenta coat the edges of the upper leaves. Its stems, with narrow wings, are red. The spikes are also red, with 5 small petals.