Corylus avellana var. heterophylla
Native to (or naturalized in) Oregon:
- Deciduous broadleaf shrub or small tree, to 23 ft (7 m) tall. Bark gray. Leaf shape is variable (hence, heterophylla = diversely leaved), i.e., oblong, elliptic, elliptic-obovate, broadly ovate, or obovate to suborbicular, 4-13 × 2.5-10 cm, papery, base cordate (wedge-shaped), margin irregularly and doubly serrate, usually lobed, upper surface glabrous (without hairs), lower surface with hairs along veins, lateral veins 3-7 on each side of midvein; petiole slender, 1-2 cm long. Male (pollen) catkins, yellow, 2-5 per cluster, pendulous, slender, ca. 4 cm long. Female flowers 2-6 in a cluster. Nut ovoid-globose, ca. as long as bracts, 0.7-1.5 cm in diam.
- Sun to part shade, adaptable to different soils, best in moist soil
- Hardy to USDA Zone 4 Native to temperate broad-leaved forests, thickets on mountain slopes in China, also found in Japan, Korea and eastern Siberia.
- This species has many similarities to C. americana, with good quality nuts with relatively open husks. Nuts from this species are collected directly from wild plants and sold on domestic markets by local people. Currently active breeding programs in Korea and China emphasize this development of genotypes derived from this species (USDA National Clonal Germplasm Repository, Corvallis, Oregon).