Expanding the National Collection in 2024
CPC and its Network of Conservation Partners continued to make remarkable strides over the past year in our shared efforts to grow the CPC National Collection in 2024—bringing even more imperiled plant species into ex situ conservation collections to secure and preserve them for future generations. In 2024, an impressive 70 new species were added to the National Collection. These new additions represent the collaborative efforts of 17 CPC Conservation Partners across 19 states and territories, showcasing the power of partnership in coordinating and prioritizing collection efforts of rare and endangered plants. Together, Conservation Partners now protect a total of 2,669 rare and endangered North American plant species—bringing us over 60% of the way toward our ambitious goal of securing all 4,400 of CPC’s targeted taxa. By working together, we continue to achieve more for rare plants than any one institution could accomplish alone!
Southern Milkweed (Asclepias viridula)
Southern Milkweed is a G2-Imperiled species native to wet prairies in Alabama and Florida, where it thrives in habitats influenced by periodic burns. As part of their efforts through the Florida Plant Rescue initiative, the Atlanta Botanical Garden’s Gulf Coast conservation team monitored a population of 97 blooming plants at the St. Joseph Bay State Buffer Preserve, noting the critical role of fire in triggering flowering after no blooms were observed the previous year. Widely dispersed or loosely clustered, many plants at the site faced significant herbivory, with over 60% experiencing damage to flowering structures. To mitigate this threat, flowers and developing pods were bagged for protection. Seed collection efforts yielded 212 seeds from 11 maternal lines for long term storage, with 90% of bagged seeds returned to the wild to ensure the population persists for years to come.
Slender-stemmed Monkeyflower (Erythranthe filicaulis)
Slender-stemmed Monkeyflower is a G2-Imperiled California endemic plant native to the High Sierra Nevada region of the California Floristic Province. It’s found in Mariposa and Tuolumne counties, near and around Yosemite National Park. This species is threatened by logging, reforestation activities involving herbicides, and possibly also by grazing and human recreation. The California Native Plant Society ranks this species as 1B—rare or endangered in California and elsewhere. Conservation scientists with California Botanic Garden (CalBG) made a wild provenance seed collection of Erythranthe filicaulis at Stanislaus National Forest this summer through the California Plant Rescue initiative. CalBG staff noted the population to be fairly small, but still managed a conservation collection now stewarded in long term storage at their seed bank.
Mogollon Thistle (Cirsium parryi ssp. mogollonicum)
Mogollon Thistle is a T1-Critically Imperiled subspecies endemic to Arizona, with a highly restricted range on the Mogollon Rim in Coconino County. Found in the understory of Ponderosa Pine forests, its habitat is often overgrown with other species and difficult to access, as observed by the team at The Arboretum at Flagstaff during a 2024 seed collecting excursion in the Coconino National Forest which identified just seven individuals, though more may exist in inaccessible locations. This rare plant is a target species of CPC’s agreement with the USDA Forest Service (USFS) to safeguard rare plant populations on Region 3 USFS lands in the Southwest. Through collaboration with CPC’s network of Conservation Partners, this initiative aims to secure material of rare taxa from USFS land in conservation-quality seed collections.
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Explore even more rare and endangered plant species in the CPC National Collection using the Rare Plant Finder tool.