The RTSPB garden hosts several endangered or threatened species.
Two of the most imperiled species are
the Dudleya varieties and the Shaw's Agave (Agave shawii).
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The Problem
Dudleya Fariniosa
California has experienced significant plant poaching in the past seven years — most notably of Dudleya succulents *3. It was once believed that the rise in Dudleya poaching was due to the succulents becoming a trendy houseplant and a status symbol, but more recently researchers have theorized that it is due to a demand from rare plant collectors in South Korea, China, Europe and the US *9. Of the 47 recognized species of Dudleyas, 32 are listed as rare, threatened, or endangered by the California Native Plant Society (CNPS) and International Union for Conservation of Nature (IUCN) *2. The wide variety of Dudleya species once covered swaths of coastal land in San Diego, where they were used by the Kumeyaay for food, hydration, ceremonial purposes, and skin ailment remedies *5, *6. Unfortunately, land development, wildfire, drought and recent poaching incidents have left certain wild Dudleya populations so decimated that the future of the species remains uncertain *3. In fact, some of the rarer wild species of the genus have faced massive poaching operations, resulting in the removal of several hundred thousand plants in a relatively short span of time *1. Poaching at this level leaves the slow growing Dudleya at risk of extinction as it cannot repopulate fast enough to keep up with the market demand.
Another native southern California species facing wild population loss is the Agave shawii ssp. shawii (Shaw’s Agave). Shaw's agaves were once an important plant for coastal-dwelling indigenous peoples until European settlers forced them away from the coast out to lands where the plants didn’t naturally exist. This separation resulted in a loss of traditional ecological knowledge (TEK) surrounding the Shawii species and its use as a food source and for cordage or other items *7. Over time, land development, erosion, and, more recently, border-wall construction devastated the slow-growing wild populations.
Shaw's Agave (Agave shawii)
By 2014, wild Agave shawii ssp. shawii populations were nearing local extinction in their endemic southern California territories and were consequently listed as seriously threatened in California CNPS and the IUCN *2, *4, *8. The species is believed to be abundant in Baja California, but only two natural populations remain in its endemic habitats in San Diego, and one of those supports only a single individual and its rosettes *2. The Baja populations are not monitored regularly and may be destroyed in the near future due to coastal development, so the preservation of this species cannot be left to hoping the Baja plants will carry on the lineage. Restoration efforts in San Diego are underway, and restored populations are growing, but the plants are not producing viable seeds. The primary issue appears to be a lack of active pollinators *8. Researchers have observed several species visit the plants, but they do not transfer pollen. Bats are thought to be the main pollinator for the Baja populations, but they have not been observed visiting our northern plants *4. Without natural pollinators, active conservation management will remain necessary indefinitely.
What RTSPB is doing to help
RTSPB will establish a seed library specifically for the Shaw’s Agave (Agave shawii ssp. shawii) and the Chalk Dudleya (Dudleya pulverulenta). This library will provide seeds and supplemental materials that explain the challenges these species face, their ecological significance, and steps San Diegan's can take to help. By offering free native Dudleya and Agave shawii ssp. shawii seed to the community, the library will directly support local restoration efforts, counteract poaching and development, and empower residents to participate in species preservation. Focusing first on these two plants, the seed library will serve as a tool to mitigate poaching and habitat loss, while maintaining the potential to expand to more native species later.
Providing native Dudleya seeds to foster local cultivation has the potential to reduce both appeal and market value of illegally sourced plants. Meanwhile, encouraging home cultivation of Shaw's Agave in San Diego will increase researchers chances of identifying suitable pollinators because establishing “safe sites” where the species can maintain a population while avoiding threats might allow them the time to establish a completely new pollinator *10.
What you can do to help
Plant!
When you plant the seeds of these threatened species you directly affect their black market sales and contribute to the restoration of their populations in our ecosystems. You can find more information on how to plant and cultivate the seeds HERE.
Spread the word!
Let people know what you've learned about the crisis facing these native plants, encourage them to find and plant ethically sourced seeds at home and direct them to this page to learn more!
Coloring pages to inspire our budding environmental stewards!
Click on the image below that you want to print and color at home!
research cited
research cited
*1 California Native Plant Society. (n.d.). Protect California Dudleya [Web page]. https://www.cnps.org/conservation/Dudleya-protection ,*2 CNPS Inventory of Rare Plants. (n.d.).California Native Plant Society. https://www.cnps.org/rare-plants/cnps-inventory-of-rare-plants , *3 McConnell, A. (2019). Hanging by a thread: California’s “liveforevers” face new threat: poachers engaged in lucrative, illegal succulent trade. U.S. Fish & Wildlife Service. FWS.gov. https://www.fws.gov/story/2019-03/hanging-thread-californias-liveforevers-face-new-threat-poachers-engaged-lucrative , *4 National Park Service. (n.d.). Shaw’s agave: A species on the edge. U.S. Department of the Interior. https://www.nps.gov/articles/shaws-agave-a-species-on-the-edge.htm , *5 Kumeyaay Garden - University of San Diego. (2025). Sandiego.edu. https://www.sandiego.edu/kumeyaay-garden/plant.php?ID=49 *6 Lance-leaved Dudleya | Nature Collective. (2019, July 27). Nature Collective. https://naturecollective.org/plant-guide/details/lance-leaved-dudleya/ *7 Shaw’s Agave (Agave shawii). (2021). INaturalist. https://www.inaturalist.org/taxa/75297-Agave-shawii , *8 Wilkinson, K. M., Reeder, N. J., & Ríos, N. (2021). Genetic diversity and conservation status of Agave shawii ssp. shawii in California and Baja California. Ecology and Evolution, 11(8), 3499–3510. https://doi.org/10.1002/ece3.7172 *9 Beckett, L. (2022, March 20). “Crime against nature”: the rise and fall of the world’s most notorious succulent thief. The Guardian. https://www.theguardian.com/us-news/2022/mar/20/california-succulent-smuggling-Dudleya
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