July 27, 2016
The Mexican Flannelbush (Fremontodendron mexicanum), a dicot, is a shrub that is native to California and Baja California. It is included in the CNPS Inventory of Rare and Endangered Plants on list 1B.1
The Mexican flannelbush was listed as endangered in 1998 primarily due to its small population size and the risk to this species’ survival from an altered fire regime. Additional threats since listing include nonnative invasive species and impacts from border control activities. These threats can be managed and represent a moderate degree of threat. At listing, there was only a single occurrence known to exist in the United States and a single occurrence known to exist in Mexico. The occurrence in the United States is partially on BLM land and partially on private land. At the time of listing, we lacked any specific information about the occurrence in Mexico. In Mexico, botanists have not been able to relocate the population that we knew of at the time of listing, and we assume the population has been extirpated. Another population has been located in coastal northwestern Baja California, Mexico, but that population supports fewer than 20 individual plants.
Two additional occurrences of Fremontodendron mexicanum in the United States were found after listing, both of which are on Otay Mountain very near the Cedar Canyon occurrence. The fire in 2003 burned the all three of the occurrences in the United States and no above ground plants survived the fire. However, plants in these occurrences successfully resprouted and continue to persist. Currently, there are approximately 6,000 F. mexicanum plants on Otay Mountain among the three occurrences, compared to fewer than 100 plants known at listing. However, infrequent surveys and the lack of any study of its population dynamics (e.g., seed production, seedling establishment and survival and response to fire) do not allow us to conclude that these factors do not pose a risk to F. mexicanum. Therefore, we recommend that the status of F. mexicanum as endangered remain unchanged at this time.
Here you can find out more about the Mexican Flannelbush.