Stemless Morning-glory
Calystegia subacaulis ssp. subacaulis
NATIVE – CA ENDEMIC
Description (Jepson, PlantID.net)
- Eudicotyledon
- Eudicots are a major lineage of flowering plants; see family for general characteristics
- Morning-glory Family (Convolvulaceae)
- Low-growing perennial herb
- Grows from a rhizome (horizontal underground stem)
- Leaves
- Arranged in a basal rosette
- Triangular-shaped and slightly-lobed
- Rounded or pointed tips
- Margins flat or slightly wavy
- Flowers
- Inflorescence (flower arrangement) of large, solitary flowers on short stems
- Each flower with 5 fused petals, twisted and pleated in bud, opening into a funnel shape
- White or cream, often tinted with light pink
- Ovary superior (above the attachment of other flower parts)
- Fruit is a capsule (a dry, multi-chambered fruit that splits open at maturity)
- Height to a few inches
Distribution
- Native and endemic (limited to) California
- Grows in grasslands, dry open scrub, or woodlands
- See Calflora for statewide observations of this plant
- Grows at elevations to 1,600 ft.
Uses (San Mateo County Parks prohibits removal of any natural material)
- Wildlife
- Visited by birds, e.g. Anna’s hummingbird (Calypte anna) and insects for nectar and pollen
- Nectar source for native bees, bumblebees, and some moths, e.g. white-lined sphinx moth (Hyles lineata)
- Larval food source (host) for some moths, e.g. morning-glory plume moth (Emmelina monodactyla)
- Visited by birds, e.g. Anna’s hummingbird (Calypte anna) and insects for nectar and pollen
Name Derivation
- Calystegia (kal-i-STEE-jee-a) – from the Greek kalux, “cup,” and stegos, “a covering,” meaning a covering or concealing cup, probably referring to the leaf-like structures (bractlets) partially concealing the sepals of some species
- subacaulis (sub-ak-AWL-is) – from the Latin sub, “below,” and caulis, “stalk or stem,” referring to the lack of an obvious stem
- Morning-glory – flower opens in the early morning
Notes
- Although members of the Morning-glory family are often vines, hill morning-glory grows in a tidy basal rosette
- Geophytes (e.g. plants growing from bulbs, corms, rhizomes, or enlarged taproots) are well adapted to survive fire, our Mediterranean climate’s long, dry summers, and extended droughts
- Above-ground growth dies back after flowering, while underground the plant survives with stored water and nutrients
- Edgewood’s hill morning-glory is classified as a subspecies
- Subspecies indicates a geographically-separated population with distinct morphological characteristics; when not isolated, interbreeding is possible
- Variety indicates a population with small morphological variations, e.g. color, seen throughout the geographic range of the species; interbreeding is possible
- In practice, botanists have not consistently applied these ranks
ID Tips
- May be confused with 2 other morning-glory species at Edgewood – hillside morning-glory (C. collina ssp. collina) and Western morning-glory (C. purpurata ssp. purpurata)
| Hill Morning-glory | Hillside Morning-glory | Western Morning-glory | |
| Growth Habit | low-growing basal rosette | low-growing basal rosette | climbing vine |
| Hairiness | not or sparsely hairy | very hairy | not hairy |
| Leaves | flat or wavy edges … rounded or pointed tips | very wavy edges … pointed tips | flat edges … pointed tips |
| Habitat | grassland and scrub | serpentine grassland and scrub | chaparral, scrub, and open woodland |
© CBowker (L), DSchiel (M), GBarton (R)
At Edgewood
- Found in grasslands and scrub
- See iNaturalist for observations of Calystegia subacaulis
- Flowers April – June
Specific References
Las Pilitas Nursery. Pollination of California native plants.
Mitchell, M. 2017. Convolvulaceae: Morning-glory family — Calystegia and Convolvulus. Monterey County Wildflowers, Trees, and Ferns – A Photographic Guide.