Calystegia peirsonii
Peirson's morning-glory, Peirson's Morning-Glory
(c) Joe Decruyenaere, some rights reserved (CC BY-SA) · licence
Family: Convolvulaceae · Type: Vine · Native
Conservation status: CNPS 4.2
Calystegia peirsonii (Peirson's morning-glory) is a native California vine in the Convolvulaceae family, recognized by small size, glaucous appearance, deeply lobed small leaves.
Peirson's morning-glory is a native perennial found in the western Transverse Ranges, northern San Gabriel Mountains, and adjacent Mojave Desert in rocky slopes at elevations of 1,000 to 1,500 meters. Flowering from May to June, this plant produces delicate white flowers 25 to 40 millimeters long with a distinctive corolla. Growing with decumbent to weakly climbing stems less than 40 centimeters tall, it emerges from an underground rhizome and appears slightly glaucous. Its leaves have narrowly triangular blades less than 2 centimeters long, with clearly defined lobes directed toward the base and a deep, narrowly rounded sinus. The plant has distinctive bracts 3 to 7 millimeters long that nearly hide the calyx, giving it a unique structural appearance.
Identification and appearance
Key characters: 13 sympatric species; key features are small size, glaucous appearance, deeply lobed small leaves
Habitat and range
Habitat: Rocky slopes
Elevation: 1000-1500 m
California counties: Los Angeles, Ventura, Marin
Bloom period
Calystegia peirsonii blooms May-Jun.
Conservation status
CNPS 4.2
How to tell it apart
vs Convolvulus: Convolvulus has smaller flowers with sharply pointed stigma lobes; Calystegia stigma lobes are blunt.; vs Ipomoea: Ipomoea stigma is a single rounded knob; Calystegia stigma has two distinct flattened lobes.; vs Datura: Datura flowers are upright with pleated edges; Calystegia flowers are smooth funnels.; vs Abronia: Abronia has clusters of small tubular flowers; Calystegia has single large funnel flowers.; vs Oenothera: Oenothera has four separate petals; Calystegia petals are fused into continuous funnel.
Frequently asked questions
Is Calystegia peirsonii native to California?
Yes. Calystegia peirsonii is native to California (recorded as native).
When does Calystegia peirsonii bloom?
Calystegia peirsonii blooms May-Jun.
Where in California does Calystegia peirsonii grow?
Calystegia peirsonii occurs in Los Angeles, Ventura, Marin, at elevations of 1000-1500 m.
What plant family does Calystegia peirsonii belong to?
Calystegia peirsonii is in the Convolvulaceae family, genus Calystegia.
Is Calystegia peirsonii rare or endangered?
Calystegia peirsonii carries California Rare Plant Rank 4.2, state rank S4.
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.