Calystegia collina subsp. oxyphylla
Mount saint helena morning-glory, Mount Saint Helena Morning-Glory
Photo: parent species Calystegia collina · (c) Adam J. Searcy, some rights reserved (CC BY) · licence
Family: Convolvulaceae · Type: Vine · Native
Conservation status: CNPS 4.2
Calystegia collina subsp. oxyphylla (Mount saint helena morning-glory) is a native California vine in the Convolvulaceae family, recognized by distinct leaf lobes and narrower bracts.
Mount saint helena morning-glory is a rare (CNPS 4.2) California native perennial found in the North Coast Ranges of Lake, Sonoma, and Napa counties in open grassy, rocky places, and oak or pine woodlands, often on serpentine soils at elevations below 600 meters. Flowering from April to June, this plant produces white to pale pink flowers 27 to 53 millimeters long with distinct corolla lobes. Growing with stems 8 to 15 centimeters tall, sometimes reaching 20 centimeters, it forms low-spreading or climbing vegetation. Its leaves have distinct lobes, with distinctive bracts 8 to 17 millimeters long that partially conceal the flower's calyx. The plant's sepals are either entirely glabrous or have strigose hairs concentrated at the center.
Identification and appearance
Key characters: 10 sympatric species; key features are distinct leaf lobes and narrower bracts
Habitat and range
Habitat: Open grassy or rocky places or in open oak/pine woodland, often serpentine
Elevation: < 600 m
California counties: Lake, Sonoma, Colusa, Napa, Marin, Mendocino
Bloom period
Calystegia collina subsp. oxyphylla blooms Apr-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 collina subsp. oxyphylla native to California?
Yes. Calystegia collina subsp. oxyphylla is native to California (recorded as native).
When does Calystegia collina subsp. oxyphylla bloom?
Calystegia collina subsp. oxyphylla blooms Apr-Jun.
Where in California does Calystegia collina subsp. oxyphylla grow?
Calystegia collina subsp. oxyphylla occurs in Lake, Sonoma, Colusa, Napa, Marin, Mendocino, at elevations of < 600 m.
What plant family does Calystegia collina subsp. oxyphylla belong to?
Calystegia collina subsp. oxyphylla is in the Convolvulaceae family, genus Calystegia.
Is Calystegia collina subsp. oxyphylla rare or endangered?
Calystegia collina subsp. oxyphylla carries California Rare Plant Rank 4.2, state rank S3.
Related species
Other California species in the same genus, family, or bioregion.
- Calystegia collina subsp. tridactylosa — Three-fingered morning-glory
- Calystegia collina subsp. venusta — South coast range morning-glory
- Calystegia felix — lucky morning- glory
- Calystegia longipes — Paiute false bindweed
- Calystegia macrostegia — Island false bindweed
- Calystegia macrostegia subsp. amplissima — Island morning-glory
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.