Avens leaves form rosettes of large, hairy green structures that are pinnately arranged. Each leaf is composed of a significant terminal leaflet accompanied by a pair of smaller leaflets. The shapes and sizes of the leaves vary depending on the species. Typically, they exhibit a rough texture with prominent veination, and their size can range broadly, making them a key feature for identifying different species within the genus. The leaves are vivid green and can measure up to 6 inches (15 cm) long.

Avens typically blooms in late spring, displaying flowers in shades of white, red, yellow, and orange. These blossoms are borne on wiry stems, forming loose clusters. The flowers can be single, double, or semi-double, varying by species. Some flowers are initially nodding and become erect, while others remain nodding or erect throughout. Deadheading can extend the bloom season into the summer. These flowers have no distinct scent and typically range from 1 to 2 inches (2.5 to 5 cm) in diameter.

The stem of avens is green, wiry, and can be either branched or unbranched. It often features fine hairs, giving it a slightly rough texture. The stems vary in thickness, typically measuring around 0.1 to 0.2 inches (2.5 to 5 mm) in diameter. They stand upright and may exhibit a slightly ribbed surface. These stems provide structural support to the plant and can reach varying heights, often between 1 to 2 feet (30 to 60 cm).

The fruit of avens is characterized by its achenes, which bear a distinctive feathery appearance. These seedheads can be quite ornamental, varying in color as they mature. Typically, the achenes are elongated and dry upon reaching maturity, equipped with fine, hair-like structures that may aid in wind dispersal. The texture is somewhat coarse to the touch, and each achene is attached to a relatively long, plumose style that contributes to the feathery look. This unique feature makes the fruit easily identifiable and can add visual interest in a garden setting.