Velvetleaf is a summer annual that grows from seed each year, attaining heights of 1 to 5 feet (0.3 to 1.5 m). Mature plants are generally unbranched and have a strong taproot and sturdy stem that becomes woody at maturity. Leaf blades are 2.4 to 7 inches (6 to 18 cm) long and 2 to 6 inches (5 to 15 cm) wide. Leaf stalks are half as long as the leaves. The plant has a strong, unpleasant odor when crushed.
Flowers of velvetleaf are about 1 inch (2.5 cm) across and singular, arising from the base of the leaf stalk. The flowers have five petals which are normally yellow to orange-yellow. Velvetleaf flowers from July to October, and seeds mature about six weeks later.
Velvetleaf reproduces from seed. A single large plant can produce up to 8,000 seeds. Seeds dropped by the parent plant are dormant at least until the following spring, but under certain conditions can remain dormant for up to sixty years. The long period of seed dormancy is primarily due to a hard seed coat. The seeds of velvetleaf are kidney shaped and lined with sparse, short hairs along the inner edges of lobes. Seeds are grey-brown to brown-black and about 1/8 inch square (3.0 to 3.6 mm long and 2.2 to 2.6 mm wide).