This gallery contains 6 photos.
The cedar quince/hawthorn rust (Gymnosporangium clavipes) is heteroecious, that is, it requires two different host species to complete its life cycle. The cedar quince/hawthorn rust winters as a stem gall on a juniper or a cedar host – its primary … Continue reading
This gallery contains 7 photos.
Black hawthorn (Crataegus douglasii) is a small shrub or tree native to North America. Members of the Crataegus genus, the hawthorns, are found throughout temperate regions of the world. Popular with gardeners, hawthorn species hybridize easily making the taxonomy of … Continue reading