Native to (or naturalized in) Oregon:
- Broadleaf deciduous shrubs, 8-15 ft (2.5-4.5 m) tall and similar width, multistemmed, slow growing. Flowers, which appear before leaves, are soft yellow and in pendulous clusters (racemes). Leaves alternate, simple, 5-10 cm long, rounded, strongly veined, margin dentate (toothed). Fruit a somewhat spherical woody capsule, about 12 mm wide, contains 2 glossy black seeds.
- Light shade, well-drained soil.
- Hardy to USDA Zone 5 (C. glabrescens) or 6 (C. puaciflora)
- Many (over 30) or several (7) species, depending upon the taxonomic authority, the more common ones being: C. glabrescens , C. puaciflora, and C. spicata.
- C. glabrescens Fragrant Winterhazel - large, 12 ft (3.6 m) or more; 10-20 flowers per 7.5 cm clusters; leaves 6-9 cm long, cordate base, 12 vein pairs, margin with bristle-like teeth which point downward; most cold hardy of the species (USDA Zone 5).
- C. pauciflora Buttercup Winterhazel - small, 4-6 ft (1.2-1.8 m) tall, similar width; 1-5 flowers per short axillary clusters, leaves 4-6 cm, 7-9 vein pairs, glabrous above, hairs on veins below.
- C. spicata Spike Winterhazel - small, 4-6 ft (1.2-1.8 m) tall, slightly greater width; 6-12 flowers per 2.5-5 cm clusters, stamens have pink filaments, anthers brown, purple or red; leaves 5-10 cm long, 6-7 vein pairs, purplish when new then a dark to blue green, glaucous (waxy bloom) and downy below.
- Some characteristics to assist in separating C. pauciflora and C. spicata.
- Corylopsis: from the Greek korylo, hazel, and opsis, appearance, referring to the similarity of the leaves in this genus to those of the