Hill Morning-glory

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) 

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

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.

General References

Calflora Database. 2014. Berkeley, California.

Calscape. 2018. California Native Plant Society.

Charters, M.L. 2015. California Plant Names: Latin and Greek Meanings and Derivations.

Charters, M.L. 2017. Southern California Wildflowers: Guide to the Pronunciation of Specific, Generic and Family Names.

Corelli, T. 2004. Flowering Plants of Edgewood Natural Preserve (2nd. ed.). Monocot Press, Half Moon Bay, California.

Dave’s Garden.

Elpel, T.J. 2013. Botany in a Day: The Patterns Method of Plant Identification. HOPS Press, Pony, Montana.

Flora of North America. efloras.org.

Harris, J.G., and M.W. Harris. 2013. Plant Identification Terminology: An Illustrated Glossary. Spring Lake Publishing, Spring Lake, Utah.

Keator, G. 2009. California Plant Families. University of California Press, Berkeley and Los Angeles, California.

Native American Ethnobotany DB.

Regents of the University of California. Jepson eFlora. Jepson Herbarium. University of California, Berkeley.