Pholistoma auritum var. arizonicum
Arizona pholistoma, Arizona Pholistoma
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Family: Hydrophyllaceae · Type: Vine · Native
Conservation status: CNPS 2B.3
Pholistoma auritum var. arizonicum (Arizona pholistoma) is a native California vine in the Hydrophyllaceae family, recognized by geographic isolation in desert habitat key.
Arizona pholistoma is a rare (CNPS 2B.3) California native annual found in the southern desert regions in desert scrub at elevations of 300 to 700 meters. Flowering from March to April, this plant produces small white to pale blue flowers less than 10 millimeters wide. Growing with delicate stems, it reaches heights of 10 to 30 centimeters with a slender, branching habit. Its leaves feature 5 to 11 distinctive rounded lobes, giving the foliage a deeply divided, intricate appearance. The small flowers and finely dissected leaves make this desert annual a subtle but intricate botanical gem.
Identification and appearance
Key characters: 2 sympatric species; geographic isolation in desert habitat key
Habitat and range
Habitat: Desert scrub
Elevation: 300-700 m
California counties: San Bernardino, Imperial, San Diego
Outside California: Arizona
Bloom period
Pholistoma auritum var. arizonicum blooms Mar-Apr.
Conservation status
CNPS 2B.3
How to tell it apart
vs Phacelia: Pholistoma has bristly fruits and long stamens protruding from flowers; Phacelia has smooth capsules and included stamens.; vs Nemophila: Pholistoma fruits are covered in stiff rough bristles; Nemophila fruits are soft and velvety.; vs Eucrypta: Pholistoma has bristly fruits and long protruding stamens; Eucrypta has smooth fruits and tiny included stamens.; vs Solanum: Pholistoma has protruding stamens from tubular flowers; Solanum has stamens forming a yellow cone in star-shaped flowers.; vs Brandegea: Pholistoma has regular 5-petaled flowers; Brandegea has separate male/female flowers with tendrils.
Frequently asked questions
Is Pholistoma auritum var. arizonicum native to California?
Yes. Pholistoma auritum var. arizonicum is native to California (recorded as native).
When does Pholistoma auritum var. arizonicum bloom?
Pholistoma auritum var. arizonicum blooms Mar-Apr.
Where in California does Pholistoma auritum var. arizonicum grow?
Pholistoma auritum var. arizonicum occurs in San Bernardino, Imperial, San Diego, at elevations of 300-700 m.
What plant family does Pholistoma auritum var. arizonicum belong to?
Pholistoma auritum var. arizonicum is in the Hydrophyllaceae family, genus Pholistoma.
Is Pholistoma auritum var. arizonicum rare or endangered?
Pholistoma auritum var. arizonicum carries California Rare Plant Rank 2B.3, state rank S3.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.