July UW Plant Profile: Calycanthus occidentalis

Each month the UW Botanic Gardens' Newsletter, E-Flora, posts in detail about a specific plant, among many other interesting posts about events and general information.

This month's feature is about the hydrangea, which can be found at the Miller Library North Foundation Bed at the Center for Urban Horticulture.



Here is the posting:

July Plant Profile: Calycanthus occidentalis

Calycanthus occidentalis or western spicebush blends into the background of the garden until the rosy buds form and swell in May and its unique solitary blooms begin unfurling in June. The burgundy blossoms are reminiscent of magnolia blooms, and like magnolias have tepals (sepals and petals that both function as petals). The scent of the flowers is also distinctive, and is reminiscent of wine gone sour. The musky odor draws in small beetles to pollinate the flowers, and rewards them with a protein-rich meal of succulent tissue at the inner base of the tepals and stamens. Calycanthus occidentalis is a locally common deciduous shrub native to the foothills of the North Coast Range and the Sierra Nevada in California, with a few populations in southern Oregon. In its native range it is an understory species, growing on moist canyon slopes, along creeks, and around lakes and ponds generally at mid to low elevations (below 4,000ft). The leaves are opposite, egg-shaped (ovate), bright green, and strongly aromatic when crushed. In the Seattle area Calycanthus occidentalis prefers full sun or light shade and moist soil. In ideal conditions plants can reach 12 feet in height and width, and will continue blooming throughout the summer months. Deer avoid Calycanthus occidentalis, likely because the plant contains toxic alkaloids including calycanthine.  Calycanthine is a stimulant of the central nervous system, and if ingested can cause painful muscle contractions or tetanic seizures. The toxin is concentrated in the seeds of the plant, and although generally animals avoid the shrub, there are some historic reports of cattle and sheep poisonings after ingestion of the seeds For more information go here.