Carpenteria californica

The genus Carpenteria is monotypic and endemic to California (Flora of North America Editorial Committee 2016).

Tree Anemone (Carpenteria californica) is endemic to the western foothills of the Sierra Nevada in eastern Fresno County and adjacent Madera County, California. Approximately eleven occurrences are believed extant, containing about 8,000 total individuals. Most occurrences are on U.S. Forest Service land (Sierra National Forest), and there are also occurrences on BLM land, on a Sierra Foothill Conservancy preserve, and on private land. Construction of subdivisions is a threat on private land, and one occurrence on BLM land is threatened by possible construction of a new San Joaquin River dam. Disruption of the natural fire cycle is a threat throughout the range; the Sierra National Forest has a controlled burning program to benefit this species, but coordinating burns on private lands can be more challenging. Livestock grazing and trampling can have severe impacts on new post-fire seedlings. Minor threats include grading of powerline access roads and ORV use.

Tree Anemone (Carpenteria californica) occurs in the western United States. It is endemic to the central and southern Sierra Nevada Foothills between the Kings and San Joaquin rivers in eastern Fresno County and adjacent Madera County, California. Range extent was estimated to be 363 square kilometers, using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1993 and 2024 (FNA 2016, CNDDB 2024, CNPS 2024, iNaturalist 2024, Jepson Flora Project 2024, SEINet 2024).

Based on herbarium records, photo-based observations, and NatureServe Network occurrence data documented between 1993 and 2024, and anecdotal evidence, there are between six and twenty occurrences rangewide; of fourteen documented occurrences, approximately eleven occurrences are believed extant (CNDDB 2024, iNaturalist 2024, SEINet 2024).

Tree Anemone (Carpenteria californica) is considered to be among the plants which are "rare, threatened, or endangered in California and elsewhere" (CNPS 2024). Development (construction of subdivisions) is a threat to plants and habitat on private land. One occurrence on BLM land is threatened by possible construction of a new San Joaquin River dam nearby. Disruption of the natural fire cycle is a threat throughout the range, particularly since this species requires fire in order to reproduce sexually. The Sierra National Forest has undertaken a program of controlled burning for this species' conservation (USFWS 1998). However, burning on private lands remains a challenge because of the landowner coordination and urban interface protection required (USFWS 1994). Also, ideally, livestock access should be restricted for several years post-burn so that seedlings are not grazed or trampled; ensuring this restriction is a challenge throughout the range. Livestock grazing and trampling does not appear to impact mature plants, but can have severe impacts on new post-fire seedlings; a three-year study documented the death of over 90 percent of 400 such seedlings predominantly due to grazing and trampling (Clines 1994 cited in USFWS 1998). The grading of access roads beneath powerlines and around power towers poses a minor threat to part of one occurrence on the Sierra National Forest. ORV use also poses a minor threat to several occurrences. Road expansion (highway widening) is a potential threat, but is unlikely to occur at a location that would impact this species prior to 2018 (USFWS 1998). Small scale logging on the privately owned lands within the boundary of the Sierra National Forest is another potential minor threat, as this activity has destroyed some plants in the past (heavy equipment driven across populations to access logging sites) (USFWS 1998). Illegal trash dumping has also occurred within two occurrences in the past and may pose a potential minor threat (USFWS 1998).