Based on an September 2020 extract of the California Plant Rescue Database, California Botanic Garden holds 1 accessions of Pholisma sonorae in orthodox seed collection. There are as many as 9931 seeds of this species in their collection - although some may have been used for curation testing or sent to back up.

Based on an August 2020 extract of the California Plant Rescue Database, California Botanic Garden has collected 1 seed accessions of Pholisma sonorae from 1 plant occurrences listed in the California Natural Diversity Database. These collections together emcompass an unknown number of maternal plants

A moderately widespread but rare parasite, known from southwestern Arizona along border with Mexico east of San Luis, southeastern California (Imperial County), northwestern Sonora and northeastern Baja California, Mexico. ""Widespread in Gran Desierto and a few locations in Arizona but low numbers within each occurrence."" (Laurenzi and Spence 2012).

Current threats to Pholisma include development (conversion of dune habitat to housing and agricultural land), and off-road vehicle use. The Imperial and Algodones dunes are located primarily on BLM lands, and although a small section of habitat has been

Only two populations are known from California and Mexico. A site documented by a herbarium specimen on U.S.-Mex. Hill was visited during 1998, and no plants were located. As the site is rather remote and undeveloped, it appears that dune stabilization by associated species has sufficiently altered the habitat to the extent that Pholisma sonorae can not grow there. Two years ago, Pholisma was located near a lemon grove, at a site documented by a herbarium specimen made by Jepson. South of the U.S.-Mexican border, far more sand dune habitat can be found, but the status of the plants is unknown for that area.

Desert Botanical Garden is currently processing seeds by hand. Collected seeds from the 1998 lot have been hand-cleaned by volunteers and counted using an analytical balance. A small mass containing hundreds of seeds were sent to Dr. Valerie Pence at Cincinnati Zoo and Botanical Garden. Seeds had been sent previously in 1987, but they had been previously frozen for an undetermined amount of time. Dr. Pence conducted tetrazolium tests on the 1987 seeds and determined that they were non-viable. Information from G. Yatskievych (pers. com., 1993) about the nature of the undifferentiated embryo, and oily endosperm led Dr. Pence to believe that freezing may have permanently damaged the seeds. Germination experiments at the Garden using rootbound host plants were also conducted on Pholisma in 1993, but no seed germinated. A dissertation on Ammobroma sonorae germination requirements by Cothrun (1969) concluded that all known and experimental methods used to germinate seed of any plant were attempted, and no germination occurred. Seeds were recollected in 2000, and are still being cleaned. There has been a recent unverified report that seeds have been germinated in vitro. Alan Smith studied the phylogenetic relationship of Pholisma spp. using molecular data generated from field-collected specimens. The resulting analysis indicates that Lennoaceae is closely related to Boraginacese.

Within the U.S boundaries, management for conservation of Pholisma sonorae is occurring in California on BLM land designated as off-limits to ATV recreational use. Elsewhere, the species is not protected.

Management needs are incredibly challenging, as dunes must remain unstabilized in order for Pholisma to persist. Increasing conversion of these dunes to agricultural fields, housing developments, highways, and recreational sites will hasten the extinction of Pholisma sonorae.

Ex situ needs are equally as challenging as management problems. Since seeds do not germinate reliably, and no means of perpetuating them in cultivation has been found, the species does not lend itself readily to ex situ conservation. For this particular species, in situ conservation efforts are the key to perpetuation.