Acanthamintha ilicifolia (San Diego thornmint) is endemic to San Diego County and the tip of northwestern Baja California. CPC Participating Institution, San Diego Zoo Global (SDZG) is conserving this plant. San Diego thornmint is an annual aromatic herb in the mint family (Lamiaceae). From April to June, it produces clusters of white, two-lipped, tubular flowers with pink markings on the lower lip. Unfortunately, over ninety percent of the available habitat for this species has been lost to development over the past century and non-native invasive plants and climate change continue to threaten the species.
In 2017, SDZG made maternal line seed collections from 4 populations in San Diego County. 2 of these collections are going to be used as part of a seed bulking project. When grown in a controlled setting this species produces copious amounts of seed. Through this bulking project 10’s of thousands of seeds will be available for augmentation of managed populations, and potentially for introduction into new or historic locations. Maternity will be tracked, and unless research directs us otherwise, the genetic diversity of different populations will be kept separate.
As of 2017, invasive species and climate change pose the largest threat to this species. While development, grazing, and trampling were certainly causes of a massive decline in population and threats at time of listing, these threats have been minimized as the species is now protected by the San Diego Multiple Species Conservation Program (MSCP) and by the laws afforded to state and federally listed endangered species. Rainfall and temperature affect germination and successful reproduction in A. ilicifolia and climate change threatens to alter these factors in the future. Prolonged drought (thought to be more common as a result of climate change) could lead to a drastic decline in numbers, resulting in inbreeding depression, genetic bottle-necks, and/or occurrence extirpations.
The conservation experts at CPC participating institutions such as the San Diego Zoo Global share their in-depth conservation expertise about rare plants through CPC’s National Collection Plant Profiles.
Researcher Stacy Anderson, from the Plant Conservation team at SDZG, collects another plant they are conserving – the Calochortus dunnii known as Dunn Mariposa Lily.