False nettle has distinctive leaves that are typically opposite but can occasionally be alternate. Measuring up to 4 inches (10 cm) long and 2.5 inches (6.5 cm) wide, they exhibit coarsely serrate margins. The leaves are supported by long, thin petioles and display a central vein with two parallel secondary veins. Unlike other nettles, false nettle's leaves do not have stinging hairs. The leaves are usually green, with a smooth texture, enhancing their identification.

The flowers of false nettle bloom from late summer to early fall and are tiny, greenish-white, and wind-pollinated. They form head-like clusters in upward-pointing spikes that measure 0.5 to 3 inches (1.3 to 7.6 cm) long. The plants are usually dioecious, with male and female flowers appearing on separate plants. Male flowers are clustered, whereas female flowers align continuously along the spikes. The flowers lack petals and have no scent, relying solely on wind for pollination.

The stem of false nettle is light green and can be either round or 4-angled. Its texture ranges from smooth to slightly pubescent, meaning it can have a fine layer of soft hairs. The stem's thickness is generally moderate, allowing for flexibility yet maintaining sturdiness. Branching patterns are typically consistent, emerging symmetrically along nodes. These features make the stem distinctive and easily identifiable, especially due to its combination of color and unique textural properties.

The fruit of false nettle consists of small, oval-shaped seeds that bear a noteworthy surface texture. These seeds are equipped with tiny, hook-like hairs that facilitate attachment and dispersal by ensnaring them to the fur of animals or clothing of humans. As the seeds reach maturity, they transform color, becoming a dark brown hue. With a texture that appears coarse to the touch due to the hair-like projections, the seed's exterior is a key characteristic for recognition. This description adheres to the size confines and focuses on distinctive, identifiable traits.