Description
Trichostema austromontanum subsp. compactum (Hidden Lake bluecurls) is an annual herb in the mint family (Lamiaceae) that was listed as threatened by the U.S. Fish and Wildlife Service (USFWS) in 1998 due to trampling and small global population size; it was delisted due to recovery in 2018. The entire range of the species is restricted to the margins of a small ephemeral lake, Hidden Lake, in the San Jacinto Mountains, Riverside County, California and occupies just 2 acres globally. Annual population estimates vary widely between years depending on total precipitation and the extent of suitable habitat along the margins of the lake. Population counts range from 75 in 2019 to 394,000 in 2017. In 2006, a partnership between California State Parks, California Botanic Garden and the USFWS was established with the goal of advancing recovery efforts and supporting the long-term conservation of the species. Conservation actions that have been implemented include 1) population monitoring and habitat monitoring at Hidden Lake, 2) new regulatory mechanism to enforce the policy of no off-trail visitation, 3) the establishment of Hidden Divide Natural Preserve within Mount San Jacinto State Wilderness 4) establishment of a multi-year ex-situ conservation seed collection at California Botanic Garden, 5) installation of interpretation panels, 5) development of a floristic inventory of the vascular plants at Hidden Lake, 6) and evaluation and continued implantation of a conservation strategy. In this presentation we will provide a summary of over 20 years of conservation action for this narrowly endemic species.

Description
From 2020 to 2024, the San Diego Natural History Museum conducted rare plant surveys in two California Department of Fish and Wildlife properties in San Diego County. These included recently acquired parcels of the 6,100-acre Hollenbeck Canyon Wildlife Area (HCWA) in the Peninsular Range foothills and the 3,250-acre Oak Grove Unit of the San Felipe Valley Wildlife Area complex in the desert transition zone northeast of Palomar Mountain. Targeted searches for special-status species yielded substantial gains in overall floristic knowledge at both sites. In HCWA expansion parcels, surveys documented 440 plant taxa and mapped 22 special-status species, including the California Rare Plant Rank 1B taxa Ericameria palmeri var. palmeri (Asteraceae), Isocoma menziesii var. decumbens (Asteraceae), Comarostaphylis diversifolia ssp. diversifolia (Ericaceae), Clarkia delicata (Onagraceae), Sphenopholis interrupta ssp. californica (Poaceae), and Pentagramma rebmanii (Pteridaceae). Incorporating historic vouchers and iNaturalist records increased the plant inventory for the entire wildlife area from 215 to 521 taxa. At Oak Grove, surveys recorded 456 plant taxa, including CRPR 1B.3 Deinandra mohavensis (Asteraceae) and two additional sensitive species. Three other reported sensitive taxa were critically evaluated and deemed unlikely to occur due to lack of voucher evidence. These results highlight how focused rare plant surveys not only clarify the distribution of special-status species but also dramatically improve site-specific floristic inventories—strengthening the baseline data needed for effective conservation planning and land management.

Description
Gaviota tarplant (Deinandra increscens subsp. villosa) is a federal and state endangered member of the sunflower family that occurs on coastal terraces and ridges along a 50-mile stretch of the Santa Barbara County coastline, centered roughly on Point Arguello at Vandenberg Space Force Base. One of the most robust populations of Gaviota tarplant occurs at The Nature Conservancy’s (TNC) Jack and Laura Dangermond Preserve (Dangermond Preserve), which is also one of only two populations on conserved land. Populations of this annual plant have high inter-annual variability, making cost-effective long-term monitoring challenging, especially over large areas. Further, the Dangermond population has some plants that exhibit intermediate morphology that do not perfectly conform to the documented morphology of Gaviota tarplant, as compared to other populations, such as those at Mariposa Reina and Tranquillon Mountain. To inform planned restoration and management activities at the Dangermond Preserve, CNPS worked with TNC, U.S. Fish and Wildlife Service, California Department of Fish and Wildlife, and other experts to develop a long-term monitoring protocol for the Dangermond Preserve population. Following preliminary surveys in 2023, the first year of protocol monitoring occurred in 2024, which included vetting, field-testing, and finalizing the methods. Final methods use a grid overlay to efficiently and simultaneously map the population extent and estimate the population size across the 1,200-acre survey area. Here, we present the methods used, including an analysis of what did not work, as well as a summary of findings from three years of data collection.

Description
Astragalus (Fabaceae) is a globally distributed genus notable for its extraordinary species richness (ca. 3,200 spp.) in Eurasia and western North America, many narrowly distributed and endemic to arid environments. Among these is Astragalus magdalenae var. peirsonii (Peirson’s milkvetch), a perennial herb restricted to sand dune ecosystems of southern California, USA, and northern Baja California, MX. Listed as Threatened under the U.S. Endangered Species Act and Endangered under the California ESA, this taxon is increasingly vulnerable to habitat fragmentation, off-highway vehicle disturbance, climate change, and low reproductive success. We combine a comprehensive, range-wide population genomic analysis with controlled pollination experiments to investigate genetic diversity, structure, and breeding system in A. m. var. peirsonii. Using high-resolution genomic data, we identify three genetically distinct subpopulations distributed on a north–south axis along the dunes, with highest genetic diversity in the northern and central regions. Patterns of structure, gene flow, and effective population size reveal spatial variation that informs vulnerability and evolutionary potential. Pollination trials demonstrate self-incompatibility, requiring cross-pollination for successful reproduction. Together, these results underscore the need to conserve multiple subpopulations, safeguard pollinators, and broaden ex situ seed collections. Our findings highlight regions where targeted seed banking and habitat protection are essential. In the face of climate change and disturbance, this study shows the value of landscape genomics for conserving narrowly distributed desert flora.

Description
This presentation illustrates the most recent endeavors by San Diego Zoo Wildlife Alliance (SDZWA) and its partners to create ex-situ collections of several rare and endangered oaks, focusing primarily on six priority oak species in Southern California, Baja California and the Channel Islands. Threats like habitat loss and fragmentation, fire, climate change and border activities are creating enormous pressure on many plant species, and oaks are no exception. Propagating these oaks begins with a range of collection activities in the field including ArcGIS mapping, collecting leaves for DNA analysis, new growth for micropropagation work, pollen collection and, of course, acorns. We collect and track multiple maternal lines to ensure genetic diversity as the ex-situ collection grows. Finding viable acorns, however, has proven to be quite challenging for some species, particularly Q. cedrosensis. This has led us to try other propagation techniques such as cuttings, air layering, micropropagation and, in one case, an in-situ oak rescue. All these propagation methods have proven successful to various degrees and have resulted in the planting of several young oaks as the start of ex-situ oak collections. We are planting oak groves at the Zoo and Safari Park and sharing seedlings with other institutions through the Global Conservation Consortium for Oak (GCCO).