Viola helenae is a small, erect, unbranched subshrub, typically reaching a 30–80 cm height. The stems are glabrous and emerge from a taproot, with some plants also rooting from the lower part of the stem. The leaves are simple, alternate, and tend to cluster toward the upper part of the stem. The leaf blades are lanceolate to elliptic-lanceolate, measuring 7.5–13 cm in length and 1.9–2.6 cm in width, with an acuminate apex and an attenuate base. The surfaces of the leaves are glabrous, and the margins are remotely callose–serrulate. It produces 1–2 flowers in the upper leaf axils. These flowers are bisexual and predominantly chasmogamous (plant reproduction in which the flowers open up, enabling cross-pollination). The calyx consists of 5 linear-lanceolate sepals that are subequal in length, approximately 4.8–5.1 mm, with the upper and lower ones slightly longer. The corolla is zygomorphic (bilaterally symmetric) with 5 distinct, unequal petals, pale lavender or white. The petals are ciliate along the claw, with the lateral and lower ones smaller than the upper pair. The staminal filaments are coherent around the ovary, with the anther connective of the lower stamens prolonged into an appendage. It bears capsules as fruits, which exhibit loculicidal dehiscence and are 9–11 mm long. The seeds are numerous, pale olive-brown, obovoid–ellipsoid, and approximately 2 mm long and 1–1.5 mm in diameter. The leathery and dull seed coat encapsulates a fleshy, oily endosperm. It is found in wet forests and shrublands in gulch bottoms, slopes, and on exposed ridgetops around 610 meters.