By NANCY CONYERS
Now that summer is here, I cannot help but reflect on the spectacular flower show Mother Nature provided this winter and spring. It seemed there was something wonderful to see around every corner. A new show every week, if not at times every day.
My typical route includes the Rim Trail past the pump house and the vernal pools. In May, a field of canchulagua was in bloom. Its species name, Zeltnera venusta, is derived from the Latin word “venustus,” meaning charming, elegant — it is all of that. Nearby, there were also fields of goldenstar (Bloomeria crocea) blooming. I don’t recall ever seeing anything like the size and number of plants in bloom in the past 10 years.
What a delight this year to see the vernal pools teeming with life. After they dried, something new appeared. If I had seen it in years past, I had not recognized it for what it was. This year, there was an explosion of purple. Not just a few flowers, but big patches. As I approached for a closer look, I could detect the strong, sweet odor of mint. I was in the midst of San Diego mesa mint.
San Diego mesa mint (Pogogyne abramsii) is an herbaceous annual with bell-shaped purple flowers with white or yellow throats and typically blooms March through June. It has been listed as an endangered species since Sept. 28, 1978. The mint is endemic to San Diego County and can be found south of Del Mar Mesa in Mira Mesa, Miramar, Kearny Mesa and Tierrasanta. Seed germination is highly dependent on the wet and dry cycles of vernal pools. Seed set is minimal in dry years, but seeds will survive several dry seasons.
Urbanization has been a major factor in the loss of vernal pool habitat. The popularity of recreational off-road vehicles including mountain bikes has also become a threat to the San Diego mesa mint. Drought, climate change and fire control are also thought to be contributing to habitat loss.
In 1998, the U.S. Fish and Wildlife Service and San Diego State University collaborated to establish the Vernal Pools of Southern California Recovery Plan. Ongoing efforts to restore and conserve vernal pools including control of nonnative plants is essential to preserve San Diego mesa mint. How fortunate we are to be able to see this work continue in Mission Trails Regional Park.
— Nancy Conyers is a trail guide at Mission Trails Regional Park.