Cheirodendron trigynum subsp. helleri is a tree growing between 5 and 15 meters tall, with secretory canals present in most parts. The leaves are palmately compound and arranged oppositely. Each leaf consists of 3–5(–7) coriaceous to chartaceous leaflets, with the midvein, margins, petiolule, and petiole usually tinged purple. The petiolule is often laterally compressed. The leaflets are ovate, elliptic to broadly ovate, or occasionally somewhat obovate, with the most prominent central leaflet measuring 5–15(–18) cm long and usually about half as wide. The apex is rounded, obtuse, or occasionally emarginate to caudate-acuminate. The base is broadly cuneate to rounded or subtruncate. The margins are somewhat thickened, entire to serrate-crenate, with strongly curved, glandular teeth usually less than 1 mm long. The veins are flat on the upper surface (slightly sunken in dried material). The petiole base is often broad and sheathing the stem. Petioles measure 5–12 cm long, while petiolules range from 1–3(–4) cm long and are subterete. Stipules are absent. The flowers are arranged in terminal, erect, oppositely branched panicles of umbellules, with inflorescences reaching up to 20(–24) cm long. The bracts are minute, subconnate, persistent, forming an involucel below the umbellules and a pseudocalyx below each flower. Pedicels measure 1.5–6 mm long. The flowers are bisexual (perfect) and functionally staminate (andromonoecious). The calyx consists of five short, basally connate teeth. The corolla has 5(6) petals, with buds dark purple and mature petals purple externally and greenish internally. The petals are valvate, caducous, triangular to ovate, or oblong, with an inflexed apex. Stamens are usually as many and alternate with the petals, though sometimes numerous. They are distinct, inserted at the edge of the epigynous nectary disk, pale yellow, and spreading. The ovary is inferior, 2(3)-carpellate, with connate carpels (rarely pseudomonomerous), each containing two pendulous ovules, one abortive. The styles are 2–(–3), measuring 1–2 mm long, distinct or connate up to about half their length, forming a short, conical stylopodium with divergent to spreading arms. The fruit is a green drupe when immature, ripening to dark purple, with a fleshy exocarp. It is globose, laterally compressed, and can be orbicular, oblate, ovoid, or obovoid, measuring 3–7.5 mm long. The pyrenes are cartilaginous, laterally compressed, and correspond in number to the styles. When dry, the fruit appears strongly ribbed, measuring 5–8 mm long, including the styles. Each pyrene contains a single seed with a small embryo. It is found in mesic to wet forests between 440-1,250 meters.