Gall Week April 20 to April 28, 2024
Spring is a good time to find galls. While the leaves are still not yet out, it is easier to see those galls that persist through the winter.
Galls are plant deformities caused by other organisms. The plant host responds to chemical secretions from the organism to build uniquely shaped structures that always benefit the gall inducer and sometimes also benefit the host.
Gall inducers can frequently be identified simply by the shape and placement of the gall plus the identity of the plant hosting the gall. Gall inducers specialize in specific groups of plants or sometimes even a single species.
Observers can use the 'Host Plant ID' observation field to add their identification of the plant host to their observation of the gall. If the id is one of the gall former species or even just the family that gall formers belong to, you have the option to choose 'Gall' under Evidence of Organism.
Many gall structure are quite small so you will need to get up close and personal to find them. Collect images of the general location and appearance of the plant deformity and then zoom in to show the specific shape and texture of the tiny structure. A single tree may have multiple different galls on its leaves and branches. Its neighbour may have still other species to find. Soon you will know where to look for species in our area and recognizing when you have discovered something new and exciting.
The Gall Week April 2024 project (https://inaturalist.ca/projects/gall-week-april-2024-event ) is a traditional projects. You will need to join the project first then add your gall observations manually.
The last few days of Gall week overlap with the first three days of this years City Nature Challenge. Check out what going on with at this link. https://inaturalist.ca/observations?project_id=182602
Happy gall hunting!
